New Delhi: The Coronavirus outbreak has threatened the world, as well as disrupted global economies, causing severe economic and market dislocation. Even as toxic pollution levels fell significantly in China between January and February (scientists think Coronavirus is a large part of the reason), satellite images collected by the National Aeronautics and Space Administration (NASA) and the European Space Agency (ESA)—and shared by NASA’s Earth Observatory—have shown a dramatic decline in pollution levels over China. This is partly due to an economic slowdown prompted by the Coronavirus, says NASA.
The images show falling levels of nitrogen dioxide amid record declines in China’s factory activity. Scientists believe that the reduction in levels of nitrogen dioxide—a noxious gas emitted by motor vehicles and industrial facilities—was first apparent near the source of the outbreak in Wuhan city, but then spread across the country. The report by the US agency has compared the first two months of 2019 with the same period this year. The space agency noted that the decline in air pollution levels coincided with restrictions imposed on transportation and business activities, and as millions of people went into quarantine. “This is the first time I have seen such a dramatic drop-off over such a wide area for a specific event,” Fei Liu, an air quality researcher at NASA’s Goddard Space Flight Center, said in a statement published on BBC News. She observed a decline in nitrogen dioxide levels during the economic recession in 2008, but that decrease was more gradual. NASA noted that China’s Lunar New Year celebrations in late January and early February have been linked to decrease in pollution levels in the past, but they normally increase once the celebrations are over. “This year, the reduction rate is more significant than in past years and it has lasted longer,” Liu said.
Factory activity in China fell at a record rate in February. The official measure of manufacturing activity—the Purchasing Manager’s Index (PMI)—dropped to 35.7 from 50 in January. It shows the virus is having a bigger impact than the financial crisis that shook the world in the last decade. PMI figures are a key indicator of a county’s economic health and can move financial markets.
The outbreak in China has affected every sector of tech manufacturing, leading analysts to reduce production estimates for everything from TVs and smartphones to laptops and videogame consoles. While there is no clear evidence, it is also believed that climate change triggered the virus to jump from animals to humans. As climate change is likely to increase the number of future epidemics caused by viruses, scientists feel the rising temperatures are making the immune system less effective.
Apart from China, Italy’s air quality and emissions have been affected. The worst out of all European countries, Italy saw a steep fall in industrial activity and road traffic, amounting to a drop in air pollution. According to the European Space Agency’s Copernicus Sentinel-5P satellite, which tracked nitrogen dioxide emissions over the continent from January 1 until March 11, north Italy’s Po Valley, the most industrialised part of the country, saw a clear decline in air pollution. All this came after a complete shutdown of services, including bars, pubs, restaurants and other venues, resulting in a reduction in traffic, air and industrial pollution.
As per air quality monitoring website AirQualityNow.eu, London also saw a drop of nitrogen dioxide from 96 on March 15 to just 20 on March 16. However, the European Public Health Alliance (EPHA) warned that dirty air in urban areas that causes hypertension, diabetes and other respiratory illness could lead to a higher overall death toll from the virus. Emissions from petrol and diesel engines were still at ‘dangerous’ levels that could imperil the most vulnerable during future pandemics.
The global health crisis has made many countries announce lockdowns. Millions have cancelled travel plans, affecting the hospitality and tourism sector, disrupting events and social gatherings. Schools have been shut too. Flights cancelled, factories closed, and several events linked to the fossil fuel industry have been postponed.
Can less travel lead to less emission? A report published last year in Reuters said commercial flying accounts for about 2.5% of global carbon emissions today but without concrete steps, that number will rise if global air travel increases. The aviation industry has set out a four-pronged plan to achieve carbon-neutral growth from 2020 and halve net emissions from 2005 levels by 2050.
If flying less or the health crisis could help reduce carbon emissions, are we prepared to face the future impact of global slowdown in the long term to achieve a low-carbon path? The financial losses due to the Coronavirus all over the world will surely drain the resources. Think about it.
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Dhaka; UN warns South Asian countries of devastating flood in forthcoming years. The countries, especially Bangladesh and India, face increased risks of more frequent and severe flooding because of climate change, a UN report said.
Bangladesh and India are among vulnerable nations that will be hit hard by droughts too due to the increased concentration of pollutants and low-quality groundwater sources.
The World Water Development Report 2020 by UN-Water, published on March 21, provides a global study of freshwater sources and analyzes the link between water and climate change.
Climate will continue to change and affect societies globally as it “will affect the availability, quality and quantity of water for basic human needs, threatening the effective enjoyment of the human rights to water and sanitation for potentially billions of people,” the report noted, urging states “to make more concrete commitments to address the challenge.”
The report pointed out that monsoon flooding in 2017 affected 40 million people in Bangladesh, India and Nepal, claiming nearly 1,300 lives and putting 1.1 million people in relief camps.
“Floods could cost South Asia as much as US$215 billion each year by 2030. Floods are also expected to contaminate water sources, destroy water points and sanitation facilities, and therefore pose a challenge to universal access to sustainable water and sanitation services,” it added.
According to Chandan Kumar Duarah, the science editor of Asomiya Pratidin, sealevel rising, cyclones and lightining death attributed to climate change will increase migration pressure in neighbouring Northeastern India, specially the adjoining province of Assam.It is seen in Assam that climate change alters habitats so that the carrying capacity of lands can no longer maintain the indigenous population. The changing situation forcing Bangladesis to migrate to resource-rich locations in adjoining northeastern India. There are few unsettled locales left on earth, so these migrants inevitably come into contact with local populations. If resources are strained already, new additions to the community are generally unwelcome. Dissimilar cultural and religious beliefs exacerbate enmity between the groups, as they fear the dissolution of their identities. This is what Assam and various populations around the world are currently experiencing.
In low-lying riverine nation like Bangladesh, flooding is a common natural disaster that affects millions and kills hundreds every year, but there are few efforts to address flooding with long-term and concrete planning, experts say.
“Since 2016, we have seen a change in weather — a gradual increase in rainfall while the level of seawater is on the rise. These are the symptoms of climate change that the UN study warns about. Sadly, our country does not have a long-term plan to address annual flooding apart from some short-term plans such as relief and rehabilitation after flooding,” Sukleash George Costa, regional director of Catholic charity Caritas Rajshahi, which covers flood-prone northern Bangladesh, told UCA News.
Dykes and river embankments are often substandard and cannot withstand strong flooding, while disaster management planning fails to address local situations due to a centralized approach, he noted.
As major rivers in South Asia are transboundary rivers, so all states in the region need to formulate and follow a joint framework for river control for greater welfare of people, Costa added.
In most cases, state and NGO efforts to tackle flooding fall flat due to a lack of proper community involvement and accountability, said a professor of geography and environmental sciences at state-run Begum Rokeya University.
Experts express serious doubts whether policymakers have enough concerns about the future state of their countries in terms of climate change compared to observers. There is no doubt about more flooding and more damage as predicated, but they don’t have a long-term plan.
Madrid: A couple of days after he arrived in Madrid, India’s Union environment minister Prakash Javadekar set the proverbial cat among the pigeons when he said countries shouldn’t be expected to revise their emissions reduction targets when nearly every other country is not on track to meeting their nationally determined contributions (NDCs) to the fight against climate change.
His words go against one of the UN’s key objectives at COP 25: to have all countries party to the Paris Agreement raise their ambitions vis-à-vis reducing emissions.
Speaking at COP25’s opening ceremony, UN secretary general António Guterres said he expected countries to show a “clear demonstration of increased ambition and commitment showing accountability, responsibility and leadership.”
“It is futile to talk about new targets right now, futile to talk about new ambitions or new programmes, unless we are able to implement our current targets under the Paris Agreement,” Javadekar said on Monday.
The UN’s recent emissions gap report estimated that if we continue to emit greenhouse gases at our current pace, the world’s surface could warm by 3.2º C on average by 2100. This is 1.7º C warmer than the Paris Agreement’s ideal threshold, which its ratifiers are expected to help meet, and 1.2º C warmer than the hard upper-limit.
According to another report by the Intergovernmental Panel on Climate Change, we have already warmed Earth’s surface by 1.1º C.
“We should concentrate more on implementing the Paris Agreement rather than bring up new issues and new subjects at this stage,” Javadekar said. He added that he thought Guterres’s expectations would be unfair to countries like India, among the very few in the world on track to achieve its self-determined Paris Agreement targets.
“We are walking the talk. On all our three targets – reduction of emissions intensity, deployment of renewable energy and the creation of carbon sinks – we are doing well. We will not only achieve our targets but overachieve them,” he said.
It’s true that India is doing better than most countries vis-à-vis meeting its Paris Agreement goals but Javadekar’s other claims are premature, to say the least. The growth of renewable energy in India has slowed in the last few years, although it remains on track to meet its sector-specific targets by 2030, but not anytime sooner, as has Javadekar claimed.
India has also faltered in the creation of new carbon sinks; its claims to having increased forest cover were padded with data that included plantations as forests.
But in a scenario where other countries, particularly developed nations, aren’t doing nearly enough to meet their NDCs, Javadekar’s argument holds in principle, that expecting India to do even more could be unfair.
He also said countries should forget their pre-2020 pledges under the Kyoto Protocol, the climate agreement in force before the Paris Agreement came to be in 2015. (The protocol required only developed countries to cut emissions.) “The rich and developed countries are falling way behind their targets. Many of them have not even fulfilled their pre-2020 targets under the Kyoto Protocol and now they want us to forget those because 2020 is already here,” Javadekar said.
“Let them start implementing their Kyoto targets even now, and fulfil them over the next two to three years. We don’t mind an extension of deadline. But the targets cannot be sidelined or pushed aside.”
This is another contentious issue at COP 25 and on which India is taking a tough negotiating stance. Developed countries haven’t delivered on their mitigation obligations under the Kyoto Protocol. With the Paris Agreement set to enter into force next year, developed countries want the slate to be wiped clean, allowing them to start over. In opposition, India and multiple less-developed countries have been demanding that developed countries achieve their emissions reduction targets.
“Every study is showing that we are nowhere close to being on track to meet the Paris targets. There is a very clear gap between what needs to be done and what is being done,” Ravi Shankar Prasad, an additional secretary at the Union environment ministry and India’s chief negotiator at COP25, told The Wire.
India wants a work programme to be set up in Madrid to ensure a framework is in place for developed countries to be able to meet their Kyoto targets even after the regime has ended. “So they can do it, say, over two years. But it needs to happen. It’s a question of equity,” Prasad said.
Javadekar is expected to raise these and other issues when he makes a statement on India’s behalf at a high-level segment at COP25 on Tuesday evening. After that, he will have to cut short his trip and come back to India to vote in the Rajya Sabha on the controversial Citizenship Amendment Bill.
Kabir Agarwal is in Madrid at the invitation of the Global Editors Network to cover COP25.
The rate glaciers are melting in the Himalaya is being significantly accelerated by lakes already formed by glacial retreat, new research led by the University of St Andrews has found.
The study, published in Scientific Reports, concluded that the glaciers which have flowed into the lakes in recent decades are retreating and thinning at a much greater rate than any other glaciers in the Himalaya.
These glaciers are responsible for as much as 30 percent of the ice loss in different parts of the mountain range, despite comprising just 10 to 15 percent of the total glacier population.
The behavior of glaciers provides the clearest indication of climatic change in high mountain regions. Long-term atmospheric warming has caused the recession of glaciers across the Himalaya.
Meltwater from glaciers in this region sustains the flow of river systems on which hundreds of millions of people depend for their basic needs.
Not all the meltwater instantly drains to downstream catchments and thousands of glacial lakes have developed and continue to expand high in the Himalaya. Until this study, the influence of glacial lakes on glacier behavior has not been thoroughly investigated in the Himalaya, despite the rapid increase in lake area and number.
Now, scientists have used declassified US Hexagon spy satellite imagery, data from the Shuttle Radar Topographic Mission in 2000 and data from modern satellites to examine the relationship between glaciers and glacial lakes since the 1970s.
The results show that glacier mass loss has occurred since at least the 1970s and has accelerated since the millennium. Glaciers in contact with glacial lakes, showed significantly higher mass loss and terminus retreat rates and are therefore likely to be driving the accelerating mass loss from the region.
Dr. Owen King, of the School of Geography and Sustainable Development at the University of St Andrews, said: “Further enhanced mass loss is very likely should the increases in the total number and area of glacial lakes continue.”
Dr. Tobias Bolch, also of the School of Geography and Sustainable Development, added: “Our results have important implications for future projections of ice loss from the region, as the interaction of glaciers and glacial lakes has not previously been considered in future glacier ice loss estimates.”
The paper, “Glacial lakes exacerbate Himalayan glacier mass loss,” by Owen King, Atanu Bhattacharya and Tobias Bolch, is published in Scientific Reports.
M Zakir Hossain Khan, senior program manager (Climate Finance Governance) at Transparency International Bangladesh (TIB), speaks to Dhaka Tribune’s Mehedi Al Amin about climate financing ahead of the COP25. This is the final instalment in a three-part series.
What is climate finance and how is it progressing?
The Copenhagen Accord and the Paris Agreement defined climate finance should be “New” and “Additional” to Official Development Assistance from the developed countries to the vulnerable least developed countries (LDCs) or developing countries. Unfortunately, that pledge was not fulfilled by the developed countries. Of the total approved projects under global climate funds, LDCs have only 23% share of the total pledged amount.
The 10 most vulnerable countries including Bangladesh have received only $1.3 billion from the Global Climate Fund (GCF). However, altogether around $10.3 billion has been pledged to GCF, and around 10% of the fund is mobilized through United Nations Framework Convention on Climate Change (UNFCCC) channels including the GCF.
What is the present scenario of climate finance for vulnerable countries? Is the 50:50 ratio of climate finance for adaptation and mitigation guaranteed?
So far, rich countries have pledged an equivalent of $30.4 billion, but only $6.8 billion has been actually disbursed. From the GCF, around $2.8 billion have been approved against the demand for around $20 billion, where Bangladesh alone needs $2.5 billion per year. There is no clear direction on how projects will be granted or in what form they will be allocated. It was already decided that the ratio of mitigation and adaptation would be 50-50, but only 24% of funds have been allocated for adaptation.
Also Read – ‘Only 2% of global climate change funds reach most vulnerable people’‘
Bangladesh is one of the most vulnerable countries to climate change. What kind of role should the nation play at the COP25 to negotiate for adequate climate finance?
We are observing that usually the developed countries are pushing the loan in contrary to the need for the most vulnerable LDCs. You might know that from the allocation of the GCF around 41% of total funding was the loan. That is contradictory to the “Polluters-Pay-Principle” of the UNFCCC. LDCs including Bangladesh should raise their voices for more grant-based finance for adaptation. Transparency and accountability of the GCF decision-making authority also need to be discussed.
How can Bangladesh properly address the loss and damage due to climate change?
The Warsaw International Mechanism for Loss and damages was adopted in the Paris Agreement. But not a single fund so far has been allocated to the growing climate change-induced loss and damage. In reverse, several international financial institutions are trying to impose insurance which will be burdensome for the climate-vulnerable community. I believe that Bangladesh along with other LDCs should demand grant-based funds to address the loss and damage. At the same time, LDCs must generate proper scientific evidence to claim their dues.
Is climate change financing a political tool in providing finance to projects to the poor countries under the harsh condition of loans?
This is a very crucial point. If you see the top 10 most vulnerable countries of the world, seven of them are either developing or poor countries. Therefore, integrated funding should be mobilized for both climate adaptation as well as development purposes. If the developed countries try to push loans as climate finance for climate-vulnerable poor countries, they would be in the “Climate-Debt-Trap,” a concern we have been raising since 2017.
Also Read – ‘Allocation, and disbursement of climate funds must be simplified’
Bangladesh has recently invested heavily in coal-based power plants which are blamed for global warming, while negotiating for climate financing as a vulnerable country. How would you explain it?
The way Bangladesh has planned to set up coal-based power plants, they will be like “carbon bombs.” After the Paris Agreement, there is no room to establish a single coal-based power plant anywhere in the world.
Bangladesh has committed to generating 100% power from renewable energy. There is plenty of opportunity in both solar and also 22,000MW wind power. Most importantly, due to several coal-based power plants near the Sundarbans, the natural shield against any natural disaster will be endangered and ultimately adaptation costs will increase.
Coal plants will not only be economically burdensome, but also devastating for the environment. Bangladesh has created an example of responsibility to address climate change issues from its resources, they should maintain that.
The Intergovernmental Panel on Climate Change (IPCC) has recently released a special report on the Ocean and Cryosphere in a Changing Climate (SROCC). This report assessed the latest scientific knowledge about the physical science basis and impacts of climate change on ocean, coastal, polar and mountain ecosystems, and the human communities that depend on them. It also evaluated their vulnerabilities and adaptation capacity and determined that the ocean and cryosphere play a critical role in sustaining life. In particular, it shows that the ocean has taken up more than 90% of the heat generated by greenhouse gas emissions and is reducing warming on land. Ocean warming, together with ocean acidification (from carbon dioxide uptake), loss of oxygen, and changes in nutrient supplies is affecting the distribution and abundance of marine life in coastal areas, including in the open ocean and at the seafloor. Glaciers and ice sheets all around the world are losing mass at an increasing rate. Warmer ocean water causes several parts of the Antarctic ice sheet to lose mass. At the same time, Greenland is losing mass due to increased surface melting. Melting ice sheets and glaciers now contribute more to the global mean sea level rise than the expansion of warming ocean waters. This shows that climate change is rapidly changing these two systems which has larger implications for humanity if remains unchecked. With this context in mind, in this piece, I will highlight the key takeaways for Hindu-Kush Himalayan Region.
Changing Cryosphere: What is in for Hindu Kush Himalayan (HKH) Region?
The term Hindu Kush Himalayan (HKH) region – which covers the high mountain chains of Central, South and Inner Asia that includes the Tien Shan, Kun Lun, Pamir, Hindu Kush, Karakoram, Himalayas, and Hengduan and the high-altitude Tibetan Plateau — has one of the world’s largest renewable supplies of freshwater. The Himalayan region has the largest reserve of water in the form of ice and snow outside the Polar Regions; this is why it is called the ‘third pole’. Based on the latest available government data sources and projections, in 2017, the population of the mountain and hills of the Hindu Kush Himalaya was about 240 million people. The total population in the ten major river basins with their headwaters in the HKH was about 1.9 billion, including the 240 million in the mountain and hills of the HKH. These big river systems, which originate in the HKH region, support irrigation in agricultural areas and provide drinking water to millions of rural and urban populations. These systems are major economic engines of the region, especially due to their large freshwater reserve, which makes it a natural resource support for the billions of people living downstream. Therefore, what happens to Himalayan glaciers has an impact on the two billion people living in Asia. It is clear that climate change is impacting the region with increased intensity, and further impacts will have severe ramifications for the economy, livelihood and ecosystem.
Below, I provide 6 important points which is reemphasised by SROCC and come from earlier findings coming from the recent researches in the region.
Water gaps are increasing: A study by HI-AWARE shows that in the 21st century alone, water consumption in downstream areas of the Indus, Ganges, and Brahmaputra (IGB) basins is projected to increase by 24%, 42% and 107%, respectively. Water use for industrial and domestic purposes is projected to increase three to seven-fold. The increase in water availability will be stronger in the upstream parts which will increase the dependency of downstream water users on upstream water resources. For example, the current blue water gap, based on unsustainable groundwater withdrawals, is 83 km3/year in the Indus and 35 km3/ year in the Ganges, and will increase by 7% and 11% towards the end of the century. There are three areas in which this process of changing climate will impact the people downstream: the water gap will increase due to socio-economic development and population rise. Secondly, while the demand will reduce, flood events will increase, and finally, heat waves will continue to rise. All these will impact those already living below poverty line the most. #2 and #3 are detailed below:
Flood events will increase: Floods will become more frequent and severe in the mountainous and downstream areas of the Indus, Ganges and Brahmaputra river basins, because of an increase in extreme precipitation events. Depending on the severity of climate change, flood events are expected to more than double towards the end of the century.
Rising temperatures: HKH regions are extremely susceptible to temperature increase. Under a 1.5 °C global warming scenario, the areas are projected to warm up by more than 2 °C on average by the end of this century. At higher altitudes this warming will be even more marked, due to the elevation dependent warming. A 2 °C global warming scenario could lead to a warming of around 2.7 °C in glaciated river basins. Currently, more likely climate change scenarios — which are specific for these river basins — suggest regional temperature increases between 3.5 and 6 °C by 2100. Most of the projections also indicate overall wetter conditions in the future and increases in extreme precipitation events. This will lead to significant losses in glacier volume, from 36 to 64%, depending on the warming scenario, and impact timing of water flows and water availability. Therefore, the rate of risk is extremely high in the present emission scenario. Heat waves are expected to increase in intensity and duration in South Asia. Already, the heat thresholds in cities have exceeded previous limits. Individual solutions for keeping houses and neighbourhoods cool will not be enough: concerted efforts are needed at the urban landscape, community and individual levels to address the challenge of increasing urban heat in South Asia.
People living far from oceans and glaciers are also impacted: It is sometimes forgotten that even people living far from the ocean or cryosphere depend on these systems. Snow and glacier melt from high mountains helps to sustain the rivers that deliver water resources to downstream populations. Due to global warming and its implications in the water resources in the HKH region, three sectors will be directly affected: water for domestic use, agriculture and hydroelectricity.
Women and poor people: One of the most striking impacts of climate change is on of women, as they are at the forefront of the economy, particularly in mountain areas. This is because men from the mountain regions are often migrants; this leaves women to manage household work and other tasks related to agriculture, natural resource management, community, and other public sphere related work—such as in markets or public institutions —that were traditionally men’s work. Land tenure and employment policies undervalue rural women’s critical roles in food security, sustainable agriculture, and natural resource management, despite women taking on the major role in these sectors. In most cases, women throughout the region do not have corresponding decision-making rights or control over resources despite shouldering both productive and reproductive workloads and responsibilities.
A combined strategy of adaptation with mitigation is key. It is unlikely that the process of climate change will be reversed, so it is best to focus on adaption. Serious policy changes and careful planning can create a climate-resilient infrastructure. The current lack of coordinated planning is currently, a major obstacle: for instance, the HKH region is trans-boundary in nature, with many watersheds are spread across different countries. Management of shared water at a trans-boundary level has its own challenges, especially when countries that fall in the watershed do not share relationships of trust. This process leads to inadequate water management at almost every level in the HKH region. At the national level, water management is marked by short-term approach, with seemingly little attention to long-term consequences. At the regional level, there is a huge scope for countries to come together — at least on river basin levels — to generate scientific knowledge in a coordinated fashion, and exercise joint policies for conservation of trans-boundary aquifer systems. This approach could benefit from system-based thinking which is lacking in the present approach. At the local level, building the community’s capacity to adapt and making infrastructure resilient is the key.
 Cryosphere is the frozen parts of our planet that includes ice and snow on land, continental ice sheets found in Greenland and Antarctica as well as ice caps, glaciers, snow and permafrost.
Reconstructions of past responses of vegetation from different ecosystems can predict the impact of climate change on weather and other environmental parameters, scientists said at the 6th Asian Dendrochronology Conference being held at the Birbal Sahni Institute of Palaeosciences in Lucknow. This is the first time that the conference is being held in India. The studies presented and deliberated at the conference were mostly from different ecological niches within Asia.
Dendrochronology is the study of tree rings that hold a wealth of information about not only a tree’s past but also that of the ecosystem in which it lives. Tree rings are layers of growth that a tree acquires in a year. The colour of old wood is always darker than a comparatively newer wood which creates a contrasting pattern of rings year on year. In the years of good growth, characterised by a healthy supply of resources, the ring is thick. It is thin when the ecosystem has dearth of resources. Trees can be great records for past and recent climates, much better than climate records as their density in a region is much greater than climate observatories and their information close enough to actual conditions.
Many of the presented papers showed a close relationship between temperature, precipitation and tree ring width. For instance, a paper on the tree growth rates in the Hengduan Mountains of South West China by Ze-Xin Fan from the Chinese Academy of Sciences (CAS), showed reduced coniferous tree ring growth under recent warming and drying climate, a phenomenon known as divergence. The paper further stated that tree growth in high latitudes and elevations is sensitive to temperatures in summer and winter season whereas tree growth in lower latitudes and elevations is sensitive to moisture in the spring season.
Another study, which brought out a 226-year long chronology of teak trees from southern Myanmar, showed that intense floods and droughts have periodically occurred in the region and their continuation or even intensification in a warming climate can lead to adverse effects on traditional agriculture and forest based economies. The authors also correlated the extreme events to large scale climate phenomenon like El Nino Southern Oscillation (ENSO), Pacific Decadal Oscillation (PDO) and sea surface temperatures of the Pacific and Indian Ocean.
Eryuan Liang, also from CAS, showed that competition among vegetation species that grow close to trees at the upper-most altitudes, often known as the treeline, could counteract the general upward movement of trees due to global warming. His research analysed the treeline position of 20 plots and found that the treelines had shifted by 0.56 m-1 m in the past 150 years. Another interesting study by Somaru Ram from Indian Institute of Tropical Meteorology, Pune, showed that increasing heat index and mean temperature during summers in Sikkim has had an adverse effect on tree growth due to high potential evapotranspiration—the rate at which plants loose water through their leaves. Such studies help scientists understand the impact of climate change at the local scale and a network of such chronologies can also help them understand climate change impacts across countries and continents. The researchers also called for the establishment of enhanced tree ring chronology networks for better cooperation.
Fioramonti told Reuters in an interview, “The entire ministry is being changed to make sustainability and climate the center of the education model. I want to make the Italian education system the first education system that puts the environment and society at the core of everything we learn in school.” He said that lessons in geography, math and physics would also be taught through the lens of sustainable development.
An outspoken climate change activist, Fioramonti received criticism for encouraging students to skip school to take part in the climate protests, according to Reuters. He said that “The 21st-century citizen must be a sustainable citizen.”
The climate change curriculum will be developed over the coming year and will include input from environmental experts. It will also vary by age group, high school will focus on the United Nations’ 2030 Sustainable Development Agenda, middle school will be learning technical information and elementary school will connect environmental stories to cultures.
In another move to help the planet, Italy said this month it would tax plastics and sugar starting in 2020.
A study reports the decline in production of principal crops under shifting cultivation (jhum) in 16 Mizoram villages beleaguered by challenges of a changing climate and population pressure.
Replacing subsistence crops with economically viable cash crops and converting shifting cultivation-land use systems into permanent plots can sustain livelihoods, the study suggests.
The indigenous farmers practicing shifting cultivation still pursue it despite lack of profits because of socio-cultural linkages, but would prefer a permanent agricultural set-up if government assistance is provided.
Shifting landscapes in the northeast are ‘cultural landscapes’ and any transformation must take into account the prevailing socio-cultural conditions of the people.
In Mizoram’s rugged mountains, telltale signs of climate change and population pressure show on slash-and-burn agriculture (jhum or shifting cultivation) and its indigenous practitioners (jhumias), who soldier on despite production and yield of principal crops taking a hit, a study has observed.
Replacing subsistence crops with profitable cash crops and converting shifting cultivation-land use systems into permanent set-ups can make agriculture potentially profitable provided that such alternatives are sustainable and worthwhile in the given socio-ecological system, the study said.
The study assesses the economic implications of shifting cultivation across the state’s eight districts and also highlights the need for proper implementation of the highly-debated New Land Use Policy (NLUP) that seeks to put an end to shifting cultivation in the state.
Running along a north-south axis, Mizoram lies in the extreme northeastern corner of India. To the south, it tapers off between Bangladesh and Myanmar. Three Indian states Manipur, Assam, and Tripura surround it to the east, north and the west.
Of 21,000 square km spread of the state, only 5.5 percent of it is arable. Compared to the 44,947 hectare that was under jhum in 2007, less than half of the area is now used for jhum. The government attributes this reduction to a switch from shifting agriculture to oil palm, sugarcane, and to activities under policies such as the NLUP.
Most survey respondents feel jhum not economically viable
For the study, as many as 815 jhumias (marginalised indigenous farmers) from 16 villages in eight Mizoram districts were interviewed during August to November 2018, on the economic viability of jhum and their perceptions of a changing climate. Satellite data was used to gauge changes in the jhum plots and abandoned patches (fallow land).
In these 16 study villages, along the precipitous slopes of Mizoram perched in the eastern Himalayas, a jhum crop system unfolds over an eight to ten-month period.
As January sets in, jhumias or marginalised shifting cultivation practitioners start clearing trees and grasses inside forests that are largely under bamboo cover in the state. These fragmented patches of land (jhumlands) roughly 0.7 hectares in area, controlled by village assemblies, are temporarily distributed to the farmers for a maximum period of two years for cultivation, the researcher said.
In March the plots are set on fire. Seeds are sown with the advent of the monsoons, generally in May, and autumn sees the harvest.
“After one cropping season is over, jhumias may continue for another crop cycle in the same plot or move on to a different patch. Following the cultivation phase, the land is left fallow for a period of three to five years. The village assembly ensures a different set of jhumias gets access to the used land after a fallow period,” study author VP. Sati of Department of Geography and Resources Management, School of Earth Sciences, Mizoram University, Aizawl, told Mongabay-India.
Sati said the jhumlands are rotated between the jhumias such that everybody gets a chance and there is scope for only one crop season in a year because agriculture is dependent on monsoon-which has become scant in the last three decades impacting crop production.
“In 26 years (till 2015), the rainfall in the state has decreased by 1.4 percent on average and the temperature has risen by 0.4 degree Celsius,” said Sati.
Coupled with the scanty rainfall, the fallow period in between jhum cycles has thinned down from 20 to 25 years to three to five years owing to a population boom which has put pressures on land availability for agriculture. The fallout of the reduced fallow period is a drop in soil fertility adding to the impacts of deficient monsoon on crop production.
“Additionally, the new generation is educated and they prefer to work in the tertiary sector,” said Sati. This leaves fewer farmers to take forward the traditional agricultural practice.
Beleaguered by these challenges, production, and yield of the eight principal crops including paddy, chili, ginger, and cabbage, grown under jhum, has declined in the last 17 years (2000–2017) in the study areas. Data shows the production of three principal crops such as paddy has gone down by 2.1 percent, ginger by 15.9 percent and chili by 5.2 percent. According to Sati, data obtained were primarily in a local measurement unit, and these were further converted into hectares. A Mizoram government document states that the most common measurement unit of area in the state is tin, which is approximately equal to an acre.
When asked about the economic viability of jhum, 95 percent of the farmers participating in the survey answered in the negative. And 88 percent of the respondents believe if the government provides financial assistance to connect the fragmented jhum plots and terrace sloppy land to transform into permanent agriculture, then the exercise may become economically beneficial.
Satellite data shows that land under permanent agriculture has remained stable during the four years (2011-2015) while a substantial decrease in active jhumlands is observed in this period. Abandoned jhumlands transitioned into degraded grasslands because shifting cultivation was not continued on these plots after the fallow period.
“Forests have depleted by four percent during the period due to the land-use changes in study villages. Shifting cultivation is practiced exclusively in forest areas. Most of them are located in bamboo forests. Every year, the forests are cut and burnt. As a result, a large-scale degradation of forest and also landscape takes place,” he said.
According to India State of Forest Report (2017), the state spread over an area of 21,087 sq km had 91.6 percent of forest cover till 2011 that dropped to almost 86 percent in 2017. The sharp decline is attributed to jhuming, encroachments and development activities.
This apart, the jhumias are also facing numerous hurdles in practicing their tradition – terrain inaccessibility, rugged and rough terrain, infertile soil, steep slopes and distance to the jhum plots. “But a large number of jhumias still practice shifting cultivation and grow subsistence cereals because of socio-cultural linkages and because they do not have other livelihood options,” said Sati.
However, DK Pandey, Department of Social Sciences, College of Horticulture and Forestry, Central Agricultural University, Pasighat, advised that shifting landscapes in the northeast are “cultural landscapeS” and any transformation must take into account the prevailing socio-cultural conditions of the people.
Pandey, who was not associated with the study emphasised that agrodiversity in shifting cultivation is one of the key factors which attract farmers to the practice.
“The shifting cultivation landscape is considered a reservoir of alternative genetic
resources which can provide more opportunities for the
wild relatives of cultivated species having the genetic potential for identifying new genes and allelic variability, as well as several other exploitable economic and environmental benefits that can be harnessed with their conservation and cultivation,” Pandey said in a study.
“Jhuming is mainly for subsistence, it doesn’t give you cash. People want cash now to fulfill their aspirations,” Pant told Mongabay-India.
Pant also elaborated on the paradox in Mizoram.
“Mizoram is the only state in the northeast where the urban population is more than the rural population. 51 percent of Mizoram’s population resides in cities, its villages are basically deserted. But the extent of jhuming is quite high in the state compared to the rest of the northeast states. People go to the jhuming areas, do the jhuming related activities and travel back,” said Pant.
“Other states have more or less reconciled to the fact that jhuming is no longer sustainable in the way it’s done now,” Pant observed.
Farmers open to switching away from jhum if supported with better policies
“With traditional crops taking a hit and population going up, the communities are experiencing food insecurity, malnutrition, and high infant mortality,” said Sati.
In the case study villages, about 37 percent of people are living below the poverty line and 17 percent of people are suffering from chronic poverty. Government data states 35.4 percent of the people in rural areas are below the poverty line, said Sati pointing out the difference in datasets.
Sati said if the ownership of jhum plots is extended to the communities for a longer period then they can switch to cash crops by terracing the jhum slopes, enabling them to foster a permanent agricultural setup that affords them greater economic gains and nutrition.
“If they have ownership, then they will be more inclined to conserve the land and practice agriculture that doesn’t harm the biodiversity,” he said.
Targetted approaches such as enhancing paddy production for food security and focusing on ginger and cabbage, which are the two important cash crops grow in Mizoram, are a few ways to bolster financial gains from agriculture.
“The production and yield of ginger and cabbage are substantial. However, due to a lack of market facilities, the economic output of ginger and cabbage is not considerable. Value addition through making spices and pickles of ginger will enhance the income and livelihood of the jhumias. Similarly, cabbage production can be increased by putting more arable land under its cultivation. Maize, mustard, pumpkin, chili, and eggplants can substantiate food requirements in the rural areas thus, their production can be increased,” explained Sati.
“Mizoram is now going for floriculture and there are some good success stories. For example, they are now exporting products such as cut flowers to southeast Asian countries. Food processing is also coming up,” added Pant.
The New Land Use Policy (NLUP) seeks to put an end to shifting cultivation, engaging people in alternative livelihoods and for granting land ownership, said Sati.
The Congress government launched the NLUP when it acquired power in 2008. It had tried to implement similar policies during its previous two tenures from 1985-1992 and 1993-1998 but without much success. The NLUP was implemented in 2011 with some modifications and a better framework following the suggestions from the Centre that envisaged a five-year-project with a staggering budget of Rs. 2,800 crores (Rs. 28 billion).
NLUP has failed to strike a chord with a section of the farmers who switched to alternative livelihood options but are now going back to shifting cultivation because of the policy’s shoddy execution.
“As Mizoram gets warmer, the importance of executing such policies an“The policy is not implemented properly because of the changes in government and misuse of funds. Shifting cultivation still continues. States such as Arunachal Pradesh and Nagaland have transformed jhumlands to permanent plots,” observed Sati. coming up with approaches that afford ownership to farmers over their lands and extending financial and technical assistance to try out agricultural innovation is the need of the hour,” professor Sati added.
A joint report from The Hamilton Project and the Stanford Institute for Economic Policy Research
INTRODUCTION: SCIENTIFIC BACKGROUND
Substantial Biophysical Damages Will Occur in the Absence of Strong Climate Policy Action
The world’s climate has already changed measurably in response to accumulating greenhouse gas (GHG) emissions. These changes as well as projected future disruptions have prompted intense research into the nature of the problem and potential policy solutions. This document aims to summarize much of what is known about both, adopting an economic lens focused on how ambitious climate objectives can be achieved at the lowest possible cost.
Considerable uncertainties surround both the extent of future climate change and the extent of the biophysical impacts of such change. Notwithstanding the uncertainties, climate scientists have reached a strong consensus that in the absence of measures to reduce GHG emissions significantly, the changes in climate will be substantial, with long-lasting effects on many of Earth’s physical and biological systems. The central or median estimates of these impacts are significant. Moreover, there are significant risks associated with low probability but potentially catastrophic outcomes. Although a focus on median outcomes alone warrants efforts to reduce emissions of GHGs, economists argue that the uncertainties and associated risks justify more aggressive policy action than otherwise would be warranted (Weitzman 2009; 2012).
The scientific consensus is expressed through summary documents offered every several years by the United Nations–sponsored Intergovernmental Panel on Climate Change (IPCC). These documents indicate the projected outcomes under alternative representative concentration pathways (RCPs) for GHGs (IPCC 2014). Each of these RCPs represents different GHG trajectories over the next century, with higher numbers corresponding to more emissions (see box 1 for more on RCPs).
The expected path of GHG emissions is crucial to accurately forecasting the physical, biological, economic, and social effects of climate change. RCPs are scenarios, chosen by the IPCC, that represent scientific consensus on potential pathways for GHG emissions and concentrations, emissions of air pollutants, and land use through 2100. In their most-recent assessment, the IPCC selected four RCPs as the basis for its projections and analysis. We describe the RCPs and some of their assumptions below:
RCP 2.6: emissions peak in 2020 and then decline through 2100.
RCP 4.5: emissions peak between 2040 and 2050 and then decline through 2100.
RCP 6.0: emissions continue to rise until 2080 and then decline through 2100.
RCP 8.5: emissions rise continually through 2100.
The IPCC does not assign probabilities to these different emissions pathways. What is clear is that the pathways would require different changes in technology and policy. RCPs 2.6 and 4.5 would very likely require significant advances in technology and changes in policy in order to be realized. It seems highly unlikely that global emissions will follow the pathway outlined in RCP 2.6 in particular; annual emissions would have to start declining in 2020. By contrast, RCPs 6.0 and 8.5 represent scenarios in which future emissions follow past trends with minimal to no change in policy and/or technology.
The four RCPs imply different effects on global temperatures. Figure A indicates the projected increases in temperature associated with each RCP scenario (relative to preindustrial levels). The figure suggests that only the significant reductions in emissions underlying RCPs 2.6 and 4.5 can stabilize average global temperature increases at or around 2°C. Many scientists have suggested that it is critical to avoid increases in temperature beyond 2°C or even 1.5°C—larger temperature increases would produce extreme biophysical impacts and associated human welfare costs. It is worth noting that economic assessments of the costs and benefits from policies to reduce CO2 emissions do not necessarily recommend policies that would constrain temperature increases to 1.5°C or 2°C. Some economic analyses suggest that these temperature targets would be too stringent in the sense that they would involve economic sacrifices in excess of the value of the climate-related benefits (Nordhaus 2007, 2017). Other analyses tend to support these targets (Stern 2006). In scenarios with little or no policy action (RCPs 6.0 and 8.5), average global surface temperature could rise 2.9 to 4.3°C above preindustrial levels by the end of this century. One consequence of the temperature increase in these scenarios is that sea level would rise by between 0.5 and 0.8 meters (figure B).
Countries’ Relative Contributions to CO2 Emissions Are Changing
The extent of climate change is a function of the atmospheric stock of CO2 and other greenhouse gases, and the stock at any given point in time reflects cumulative emissions up to that point. Thus, the contribution a given country or region makes to global climate change can be measured in terms of its cumulative emissions.
Up to 1990, the historical responsibility for climate change was primarily attributable to the more-industrialized countries. Between 1850 and 1990, the United States and Europe alone produced nearly 75 percent of cumulative CO2 emissions (see figure C). Such historic responsibility has been a primary issue in debates about how much of the burden of reducing current and future emissions should fall on the shoulders of developed versus developing countries.
<img class=”aligncenter wp-image-619313 size-article-outset lazyload” src=”https://i1.wp.com/www.brookings.edu/wp-content/uploads/2019/10/20191018_ES_THP_ClimateFacts_Figure_C.jpg” alt=”Share of Cumulative CO2 Emissions by Geographic Region, 1850-1990 and 1850-2017″ />
Although the United States and other developed nations continue to be responsible for a large share of the current excess concentration of CO2, relative contributions and responsibilities are changing. As of 2017, the United States and Europe accounted for just over 50 percent of cumulative CO2 emitted into the atmosphere since 1850. A reason for this sharp decline (as indicated in figures C and D) is that CO2 emissions from China, India, and other developing countries have grown faster than emissions from the developed countries (though amongst major economies, the United States has one of the highest rates of per capita emissions in the world and is far ahead of China and India [Joint Research Centre 2018]). Therefore, it seems likely that in order to avert the worst effects of climate change, emissions reduction efforts will be required by both historic contributors—the United States and Europe—as well as more recently developing countries such as China and India.
<img class=”aligncenter wp-image-619313 size-article-outset lazyload” src=”https://i1.wp.com/www.brookings.edu/wp-content/uploads/2019/10/20191018_ES_THP_ClimateFacts_Figure_D.jpg” alt=”Annual CO2 Emissions by Geographic Region, 1950-2017″ />
Nations’ Pledges under the Paris Agreement Imply Significant Reductions in Emissions, but Not Enough to Avoid a 2°C Warming
The future of climate change might seem dismal in light of the recent increase in global emissions as well as the potential future growth in emissions, temperatures, and sea levels under RCPs 6.0 and 8.5. Failure to take any climate policy action would lead to annual emissions growth rates far above those that would prevent temperature increases beyond the focal points of 1.5°C and 2°C (figure E). As indicated earlier, cost-benefit analyses in various economic models lead to differing conclusions as to whether it is optimal to constrain temperature increases to 1.5°C or 2°C (Nordhaus 2007, 2016; Stern 2006). Fortunately, countries have been taking steps to combat climate change, referred to in figure E as “Current policy” (which includes policy commitments made prior to the 2015 Paris Agreement). Comparing “No climate policies” and “Current policy” shows that the emissions reduction implied by current policies will lead to roughly 1°C lower global temperature by the end of the century. A large share of this lowered emission path is attributable to actions by states, provinces, and municipalities throughout the world.
Further reductions are implied by the 2015 Paris Agreement, under which 195 countries pledged to take additional steps. The Paris Agreement’s pledges, if met, would keep global temperatures 0.5°C lower than “Current policy” and about 1.5°C lower than “No climate policy” in 2100 (see figure E). Although this can be viewed as a positive outcome, a morenegative perspective is that these policies would still allow temperatures in 2100 to be 2.6 to 3.2°C above preindustrial levels—significantly above the 1.5 or 2.0°C targets that have become focal points in policy discussions.
In the following set of facts, we describe the costs of climate change to the United States and to the world as well as potential policy solutions and their respective costs.
Fact 1: Damages to the U.S. economy grow with temperature change at an increasing rate.
The physical changes described in the introduction will have substantial effects on the U.S. economy. Climate change will affect agricultural productivity, mortality, crime, energy use, storm activity, and coastal inundation (Hsiang et al. 2017).
In figure 1 we focus on the economic costs imposed by climate change in the United States for different cumulative increases in temperature. It is immediately apparent that economic costs will vary greatly depending on the extent to which global temperature increase (above preindustrial levels) is limited by technological and policy changes. At 2°C of warming by 2080–99, Hsiang et al. (2017) project that the United States would suffer annual losses equivalent to about 0.5 percent of GDP in the years 2080–99 (the solid line in figure 1). By contrast, if the global temperature increase were as large as 4°C, annual losses would be around 2.0 percent of GDP. Importantly, these effects become disproportionately larger as temperature rise increases: For the United States, rising mortality as well as changes in labor supply, energy demand, and agricultural production are all especially important factors in driving this nonlinearity.
Looking instead at per capita GDP impacts, Kahn et al. (2019) find that annual GDP per capita reductions (as opposed to economic costs more broadly) could be between 1.0 and 2.8 percent under IPCC’s RCP 2.6, and under RCP 8.5 the range of losses could be between 6.7 and 14.3 percent. For context, in 2019 a 5 percent U.S. GDP loss would be roughly $1 trillion.
There is, of course, substantial uncertainty in these calculations. A major source of uncertainty is the extent of climate change over the next several decades, which depends largely on future policy choices and economic developments—both of which affect the level of total carbon emissions. As noted earlier, this uncertainty justifies more aggressive action to limit emissions and thereby help insure against the worst potential outcomes.
It is also important to highlight what figure 1 leaves out. Economic effects that are not readily measurable are excluded, as are costs incurred by countries other than the United States. In addition, if climate change has an impact on the growth rate (as opposed to the level) of output in each year, then the impacts could compound to be much larger in the future (Dell, Jones, and Olken 2012).
Fact 2: Struggling U.S. counties will be hit hardest by climate change.
The effects of climate change will not be shared evenly across the United States; places that are already struggling will tend to be hit the hardest. To explore the local impacts of climate change, we use a summary measure of county economic vitality that incorporates labor market, income, and other data (Nunn, Parsons, and Shambaugh 2018), paired with county level costs as a share of GDP projected by Hsiang et al. (2017).
Figure 2 shows that the bottom fifth of counties ranked by economic vitality will experience the largest damages, with the bottom quintile of counties facing losses equal in value to nearly 7 percent of GDP in 2080–99 under the RCP 8.5 scenario (a projection that assumes little to no additional climate policy action and warming of roughly 4.3°C above preindustrial levels). Counties that will be hit hardest by climate change tend to be located in the South and Southwest regions of the United States (Muro, Victor, and Whiton 2019). Rao (2017) finds that nearly two million homes are at risk of being underwater by 2100, with over half of those being located in Florida, Louisiana, North Carolina, South Carolina, and Texas. More-prosperous counties in the United States are often in the Northeast, upper Midwest, and Pacific regions, where temperatures are lower and communities are less exposed to climate damage.
An important limitation of these estimates is that they assume that population in each county remains constant over time (Hsiang et al. 2017). To the extent that people will adjust to climate change by moving to less-vulnerable areas, this adjustment could help to diminish aggregate national damages but may exacerbate losses in places where employment falls. Moreover, the limited ability of low-income Americans to migrate in response to climate change exposes them to particular hardship (Kahn 2017).
The concentration of climate damages in the South and among low-income Americans implies a disproportionate impact on minority communities. Geographic disadvantage is overlaid with racial disadvantage (Hardy, Logan, and Parman 2018), and Black, Latino, and indigenous communities are likely to bear a disproportionate share of climate change burden (Gamble and Balbus 2016).
Fact 3: Globally, low-income countries will lose larger shares of their economic output.
Unlike other pollutants that have localized or regional effects, GHGs produce global effects. These emissions constitute a negative spillover at the widest scale possible: For example, emissions from the United States contribute to warming in China, and vice versa. Moreover, some places are much more exposed to economic damages from climate change than are other places; the same increase in atmospheric carbon concentration will cause larger per capita damages in India than in Iceland.
This means that carbon emissions and the damages from those emissions can be (and, in fact, are) distributed in very different ways. Figure 3 shows impacts on per capita GDP based on a study of the GDP growth effects of warming, highlighting the relatively high per capita income reductions in Latin America, Africa, and South Asia (though higher-income countries would lose more absolute aggregate wealth and output because of their higher levels of economic activity). The figure also uses a higher estimate of potential economic damages that takes into account impacts on productivity and growth that accumulate over time as opposed to looking at snapshots of lost activity in a given year. Thus, the estimates are higher than those presented in facts 1 and 2, highlighting both the uncertainty and the potentially disastrous outcomes that are possible.
Beyond showing the potentially destructive scale, this map suggests global inequity: Several of the regions that contribute relatively little to the climate change problem—regions with relatively low per capita emissions—nevertheless suffer relatively high climate damages per capita.
Fact 4: Increased mortality from climate change will be highest in Africa and the Middle East.
The reductions in economic output highlighted in fact 3 are not the only damages expected from climate change. One important example is the effect of climate change on mortality. In places that already experience high temperatures, climate change will exacerbate heat-related health issues and cause mortality rates to rise.
Figure 4 relies on estimates from Carleton et al. (2018) to show climate change’s expected effects on mortality in 2100. The geographical distribution of the impact on mortality is very uneven. Some of the most-significant impacts are in the equatorial zone because these locations are already very hot, and high temperatures become increasingly dangerous as temperatures rise further. For example, Accra, Ghana is projected to experience 160 additional deaths per 100,000 residents. In colder regions, mortality rates are sometimes predicted to fall, reflecting decreases in the number of dangerously cold days: Oslo, Norway is projected to experience 230 fewer deaths per 100,000. But for the world as a whole, negative effects are predominant, and on average 85 additional deaths per 100,000 will occur (Carleton et al. 2018).
Also evident in figure 4 is the role of income. Wealthier places are better able to protect themselves from the adverse consequences of climate change. This is a factor in projections of mortality risk from climate change: the bottom third of countries by income will experience almost all of the total increase in mortality rates (Carleton et al. 2018).
Mortality effects are disproportionately concentrated among the elderly population. This is true whether the effects are positive (when dangerously cold days are reduced) or negative (when dangerously hot days are increased) (Carleton et al. 2018; Deschenes and Moretti 2009).
Fact 5: Energy intensity and carbon intensity have been falling in the U.S. economy.
The high-damage climate outcomes described in previous facts are not inevitable: There are good reasons to believe that substantial emissions reductions are attainable. For example, not only has the emissions-to-GDP ratio of the U.S. economy declined over the past two decades, but during the last decade the absolute level of emissions has declined as well, despite the growth of the economy. From a peak in 2007 through 2017, U.S. carbon emissions have fallen 14 percent while output grew 16 percent (Bureau of Economic Analysis 2007–17; U.S. Environmental Protection Agency [EPA] 2007–17; authors’ calculations). This reversal was produced by a combination of declining energy intensity of the U.S. economy (figure 5a) and declining carbon intensity of U.S. energy use (figure 5b). However, emissions increased in 2018, which suggests that sound policy will be needed to continue making progress (Rhodium Group 2019).
U.S. energy intensity (defined as energy consumed per dollar of GDP) has been falling both in times of economic expansion and contraction, allowing the economy to grow even as energy use falls. This has been crucial for mitigating climate change damages (CEA 2017; Obama 2017). Some estimates suggest that declining energy intensity has been the biggest contributor to U.S. reductions in carbon emissions (EIA 2018). Technological advancements and energy efficiency improvements have in turn driven the reduction in energy intensity (Metcalf 2008; Sue Wing 2008).
At the same time that energy intensity has fallen, the carbon intensity of energy use has also fallen in each of the major sectors (shown in figure 5b). Improved methods for horizontal drilling have led to substantial increases in the supply of low-cost natural gas and less use of (relatively carbon-intensive) coal (CEA 2017). Technological advances have also helped substantially reduce the cost of providing power from renewable energy sources like wind and solar. From 2008 to 2015, roughly two thirds of falling carbon intensity in the power sector came from using cleaner fossil fuels and one third from an increased use of renewables (CEA 2017). Non-hydro-powered renewable energy has risen substantially over a short period of time, from 4 percent of all net electricity generation in 2009 to 10 percent in 2018 (EIA 2019a; authors’ calculations).
Fact 6: The price of renewable energy is falling.
The declining cost of producing renewable energy has played a key role in the trends described in fact 5. Figure 6 shows the declining prices of solar and wind energy—not including public subsidies—over the 2010–17 period. Because these price decreases have followed largely from technology induced supply increases, solar and wind energy now play a more-important role in the U.S. energy mix (CEA 2017). In many settings, however, clean energy remains more expensive on average than fossil fuels (The Hamilton Project [THP] and the Energy Policy Institute at the University of Chicago [EPIC] 2017), highlighting the need for continued technological advances.
The increasing share of renewables in energy supply is due in part to cost-reducing advances in technology and increased exploitation of economies of scale. Government subsidies—justified by the social costs of carbon emissions—for renewable energy have also played a role. When the negative spillovers from CO2 emissions are incorporated into the price of fossil fuels, many forms of clean energy are far cheaper than many fossil fuels (THP and EPIC 2017). However, making a much broader use of clean energy faces technological hurdles that have not yet been fully addressed. Renewable energy sources are in many cases intermittent—they make power only when the wind blows or the sun shines—and shifting towards more renewable energy production may require substantial improvements in battery technology and changes to how the electricity market prices variability (CEA 2016). The technological developments that drive falling clean energy prices are the product of public and private investments. In a Hamilton Project policy proposal, David Popp (2019) examines ways to encourage faster development and deployment of clean energy technologies.
Fact 7: Some emissions abatement approaches are much more costly than others.
There are many ways to reduce net carbon emissions, from better livestock management to renewable fuel subsidies to reforestation. Each of these abatement strategies comes with its own costs and benefits. To facilitate comparisons, researchers have calculated the cost per ton of CO2-equivalent emissions. We show high and low estimates of these average costs in figure 7, reproduced from Gillingham and Stock (2018).
Less-expensive programs and policies include the Clean Power Plan—a since-discontinued 2014 initiative to reduce power sector emissions—as well as methane flaring regulations and reforestation. By contrast, weatherization assistance and the vehicle trade-in policy Cash for Clunkers are more expensive (see figure 7). It is important to recognize that some policies may have goals other than emissions abatement, as with Cash for Clunkers, which also aimed to provide fiscal stimulus after the Great Recession (Li, Linn, and Spiller 2013; Mian and Sufi 2012).
But when the goal is to reduce emissions at the lowest cost, economic theory and common sense suggest that the cheapest strategies for abating emissions should be implemented first. State and federal policy choices can play an important role in determining which of the options shown in figure 7 are implemented and in what order.
A common approach is to impose certain emissions standards—for example, a low-carbon fuel standard. The difficulty with this approach is that, in some cases, standards require abatement methods involving relatively high costs per ton while some low-cost methods are not implemented. This can reflect government regulators’ limited information about abatement costs or political pressures that favor some standards over others. By contrast, a carbon price—discussed in facts 8 through 10—helps to achieve a given emissions reduction target at the minimum cost by encouraging abatement actions that cost less than the carbon price and discouraging actions that cost more than that price.
However, policies other than a carbon price are often worthy of consideration. In a Hamilton Project proposal, Carolyn Fischer describes the situations in which clean performance standards can be implemented in a relatively efficient manner (2019).
Fact 8: Numerous carbon pricing initiatives have been introduced worldwide, and the prices vary significantly.
At the local, national, and international levels, 57 carbon pricing programs have been implemented or are scheduled for implementation across the world (World Bank 2019). Figure 8 plots some of the key national and U.S. subnational initiatives, showing carbon taxes in green and cap and trade in purple. By imposing a cost on emissions, a carbon price encourages activities that can reduce emissions at a cost less than the carbon price.
Immediately apparent from figure 8 is the wide range of the carbon prices, reflecting the range of carbon taxes and aggregate emissions caps that different governments have introduced. At the highest end is Sweden with its price of $126 per ton; by contrast, Poland and Ukraine have imposed prices just above zero. A sufficiently high carbon price would change the cost-benefit assessment of some existing nonprice policies, as described in a Hamilton Project proposal by Roberton Williams (2019).
A crucial question for policy is the appropriate level of a carbon price. According to economic theory, efficiency is maximized when the carbon price is equal to the social cost of carbon. In other words, a carbon price at that level would not only facilitate the adoption of the lowest-cost abatement activities (as discussed under fact 7) but would also achieve the level of overall emissions abatement that maximizes the difference between the climate-related benefits and the economic costs. Although setting the carbon price equal to the social cost of carbon maximizes net benefits, the monetized environmental benefits also exceed the economic costs when the carbon price is below (or somewhat above) the optimal value.
Estimates of the social cost of carbon depend on a wide range of factors, including the projected biophysical impacts associated with an incremental ton of CO2 emissions, the monetized value of these impacts, and the discount rate applied to convert future monetized damages into current dollars. As of 2016, the Interagency Working Group on Social Cost of Carbon—a partnership of U.S. government agencies—reported a focal estimate of the social cost of carbon (SCC) at $51 (adjusted for inflation to 2018 dollars) per ton of CO2 (indicated by the dashed line in figure 8).
Fact 9: Most global GHG emissions are still not covered by a carbon pricing initiative.
Just as important as the carbon price is the share of global emissions facing the price. Many countries do not price carbon, and in many of the countries that do, important sources of emissions are not covered. When implementing carbon prices, policymakers have tended to start with the power sector and exclude some other emissions sources like energy-intensive manufacturing (Fischer 2019).
The carbon pricing systems that do exist are not evenly distributed across the world (World Bank 2019). Programs are heavily concentrated in Europe, Asia, and, to a lesser extent, North America. This distribution aligns roughly with the distribution of emissions, though the United States is an outlier: as discussed in the introduction, Europe has generated 33 percent of global CO2 emissions since 1850, the United States 25 percent, and China 13 percent (Ritchie and Roser 2017; authors’ calculations). According to currently scheduled and implemented initiatives, in 2020 the United States will be pricing only 1.0 percent of global GHG emissions; by comparison, Europe will be pricing 5.5 percent, and China will be pricing 7.0 percent (see figure 9).
Figure 9 shows each region’s priced emissions—including both implemented and planned (in 2020) carbon pricing—as a share of total global emissions. Between 2005 and 2012, the European Union’s cap and trade program was the only major carbon pricing program. However since the Paris Agreement, there has been a growing number of implemented and scheduled programs, with the largest of these being China’s national cap and trade program set to take effect in 2020. Despite this activity, it is likely that a carbon price will still not be applied to 80 percent of global emissions of GHGs in 2020 (World Bank 2019; authors’ calculations).
Fact 10: Proposed U.S. carbon taxes would yield significant reductions in CO2 and environmental benefits in excess of the costs.
To assess proposals for a national U.S. carbon price, it is important to understand the size of the likely emissions reduction. Figure 10 shows projections of emissions reductions from Barron et al. (2018) under different assumptions about the level and subsequent growth rate of a U.S. carbon price. Over the 2020-30 period a carbon tax starting at $25 per ton in 2020 and increasing at 1 percent annually above the rate of inflation achieves a reduction in CO2 of 10.5 gigatons, or an 18 percent reduction from the baseline (emissions level in 2005). A more-ambitious $50 per ton price, rising at 5 percent subsequently, would reduce near-term emissions by an estimated 30 percent.
A major attraction of using carbon pricing to achieve emissions reductions (as compared to adopting standards and other conventional regulations for this purpose) is its ability to induce the market to adopt the lowest-cost methods for reducing emissions. As of late 2019, nine U.S. states participate in the Regional Greenhouse Gas Initiative (RGGI), in which electric power plants trade permits that currently have a market price of around $5.20 per short ton of carbon 10. Proposed U.S. carbon taxes would yield significant reductions in CO2 and environmental benefits in excess of the costs. (RGGI Inc. 2019). That means that electric power plants covered under the RGGI are able to find methods of emissions abatement at a cost of $5.20 per ton at the margin and would buy permits at that price rather than undertake any abatement opportunities at a higher cost. A lower aggregate cap—or a higher carbon tax—would continue to select for the abatement approaches that have the lowest costs per ton for a given sector.
Even at much higher levels, emissions pricing leads to environmental benefits—reduced climate and other environmental damages—that exceed the economic sacrifices involved (i.e., the expense of reducing emissions). A central estimate of the social cost of carbon (in 2018 dollars) is $51 per ton (Interagency Working Group on Social Cost of Carbon 2016). However, many recent proposals have tended to entail carbon prices below this level. Goulder and Hafstead (2017) find that a U.S. carbon tax of $20 per ton in 2019, increasing at 4 percent in real terms for 20 years after that, yields climate related benefits that exceed the economic costs by about 70 percent.
The authors did not receive financial support from any firm or person for this article or from any firm or person with a financial or political interest in this article. None of the authors is currently an officer, director, or board member of any organization with a financial or political interest in this article.