A landmark decision
As many as 123 countries signed a new declaration on climate and health to recognise the linkage between climate change and public health. They did this on the eve of the first-ever “Health Day” at the 28th Conference of the Parties (COP28) to the United Nations Framework Convention on Climate Change (UNFCCC) held during November 30-December 12, 2023 in Dubai. The COP28 Presidency and the World Health Organization (WHO) together issued the “COP28 UAE Declaration on Climate and Health”, which aims to accelerate action to protect public health and communities from the growing climate impacts and strengthen healthcare systems to cope with the effects of extreme heat, air pollution, infectious and zoonotic diseases and environmental risk factors. The process of this initiative has been supported by a group of “champion countries” that include India, Brazil, US, UK, Germany, Netherlands, Egypt, Kenya, Sierra Leone and Fiji.
The declaration states that devastating health impacts are already evident from the almost 9 million annual deaths from air pollution and exposure of 189 million people to extreme weather events annually. This indicates that the protection of health has to become central to climate action. This new declaration seeks policy intervention to build more climate-resilient health systems, cross-sectoral collaboration to reduce emissions, maximise the health benefits of climate action and increase finance for climate and health solutions. Signatories have also committed to incorporate health targets in their national climate plans and improve international collaboration to address the health risks of climate change and monitor progress in all global forums including future cops and health ministerial. The significant aspect of this initiative is the effort made to get commitments on finance. Collectively, a wide range of partners and stakeholders have committed to dedicate $1billion to meet the growing needs of the climate-health crisis.
Guiding principles have also been laid on the table to support financing of climate and health solutions more sustainably. The stakeholders include governments, development banks, multilateral institutions, philanthropies and non-profits. The focus on health action is expected to catalyse action to cut emissions, accelerate energy decarbonisation, reduce waste in the health sector and lead to better integration of health considerations in climate policies. This can result in improved adaptation across sectors, including water and sanitation, housing, urban planning, food and agriculture, transport and energy. This underscores equity-based comprehensive health system responses.
Efforts to integrate climate action with health protection started way back in 2016. That is when the who along with the Government of France, which then held the cop presidency, had jointly hosted the second global conference on health and climate to build healthier societies through implementation of the Paris Agreement. There was a plea to use the Paris climate treaty also as a public health treaty. The who had warned that as per the Global Burden of Disease study, which is a collaboration of over 3,600 researchers from 145 countries, 23 per cent of the global deaths were linked to the environment including air pollution that was further worsened by climate change. Moreover, climate change was likely to kill an additional 250,000 or more people each year by 2030. Most of these deaths would occur due to climatic stress, food insecurity and vector-borne diseases. Deaths and devastations from extreme weather events would magnify the health burden several times in the developing world and would erode economic gains especially in low income countries and island nations. The spotlight was on air pollution that kills around 9 million globally today and is also a climate rogue.
New warmer
Of late, the short-lived climate pollutants (SLCP) have been under debate from global warming perspective. Black carbon is the most prominent of them. The Intergovernmental Panel on Climate Change (IPCC) has long recognised methane, nitrous oxide and hydrofluorocarbons as greenhouse gases, but in the mid-2000s it also included black carbon, which is a product of incomplete combustion of carbonaceous fuels due to low temperature. Black carbon is the solid carbonaceous fraction of particulate matter of less than 10 micrometre size (PM10) or less than 2.5 micrometre (PM2.5), which strongly absorbs light and converts that energy to heat. PM2.5 harms the global population who breathe air that does not meet the who air quality guidelines. Black carbon is short-lived, lasting up to minutes, hours, a week or a little more in the atmosphere. In contrast, CO2 emitted today can impact future climate for 30 to over 100 years. Black carbon is emitted from combustion processes, dust-generating activities and secondary particulates (like nitrates and sulphates). The composition of black carbon varies with the type of fuel used, combustion process, and emission control technologies or practices.
IPCC’s Sixth Assessment Report (AR6) provides details on a range of impacts of black carbon, including warming, snow melt and effect on precipitation, among others. As per literature, black carbon absorbs light, converts it into heat and warms up the surrounding atmosphere. Scientists calculate the potential to cause global warming in terms of “radiative forcing”, which is the difference of sunlight absorbed and energy radiated back in watts per square metre of surface. The IPCC AR5 report, while quantifying the warming potential of each pollutant, stated that black carbon can be 900 times more warming than CO2 in a 20-year time horizon. The IPCC estimates of radiative forcing are said to be conservative compared to the others in the published literature. Nonetheless, SLCPs such as black carbon absorb substantially more heat than CO2 to spike the global warming curve in the near term. As emissions and concentration of black carbon is not uniform across all regions, their effect is also more regional compared to the global impact of the more ubiquitous CO2. As long as they are in the atmosphere, their effects on the climate can be strong. Scientists point out that there is uncertainty in the emission metrics such as Global Warming Potential (GWP) and Global Temperature Change Potential (GTP) of black carbon and its potential to cause climate change. This may lead to variability in quantification of effects of black carbon on climate systems in different regions of the world. But overall, its impacts are undeniable.
Black carbon can also accelerate ice melt when it settles on snow. Bright snow surfaces reflect a high amount of solar energy back into space. But black carbon absorbs a substantial fraction of this energy and re-emits it as heat. The Arctic and the Himalayas are therefore hugely vulnerable. Black carbon on glacial snow can alter the melt cycle of glaciers and affect the water balance and water supply through seasons. These regional impacts affected by the local trend of pollution and movement of pollution are a matter of concern. Black carbon is also known to interfere with cloud formation and rainfall patterns, and may change precipitation and surface visibility. Scientists explain that emissions can suppress convection and stabilise the atmosphere in ways that may impede normal precipitation patterns. Scientists describe this as dimming of the earth’s surface, which reduces patterns of evaporation that make clouds. If black carbon heats up the layer of the atmosphere where clouds are forming, for example, the clouds will evaporate. Not being able to reflect sunlight back into space, soot-laced clouds end up warming the atmosphere. But black carbon that hangs above low-lying clouds stabilises the layer of air on top of the clouds, promoting their growth. These clouds, like shields, block incoming sunlight. As a result, black carbon also ends up cooling the planet.
There are now several studies and evidence that provide insight into the varied impacts of black carbon. Regional level impacts on cloud formation, rainfall pattern and weather, snow melt and water systems can be high and varied. As IPCC AR6 points out, in the northern hemisphere black carbon is likely to lead to early springtime snow melt but the magnitude is uncertain. In South Asia, absorbing particles may be influencing precipitation patterns. In the Tibetan Plateau it may cause changes in circulation and darkening of snow and contribute towards glacier melting, though the magnitude is not clear. All these effects will require locally appropriate action. The US-based Scripps Institution of Oceanography has further pointed towards trans-boundary movement of black carbon on the basis of aircraft-based studies and modelling. It finds that as altitude increases, the fraction of total black carbon that originates in Asia also increases. When pollution reaches the boundary layer, it becomes stable and travels long distances. At ground level, black carbon is more from local sources.
Operationalise the health agenda
If health is integrated with climate action, it can help target opportunities for mitigation and adaptation across sectors, promote integrated health mitigation strategies, strengthen core public health systems and scale up more aligned decarbonisation action. More evidence based action on health risks and benefits can support decision making. Global governance can work more effectively for the larger public good and well-being. This can not only facilitate the global finance flow but also influence national budgets and action to address the high health costs from climate change. Clearly, health can be a powerful lever to mainstream equity across multi-sector solutions.
The UN Environment Programme (UNEP) has already convened the Climate and Clean Air Coalition with support from other global agencies and multilateral bodies that have membership of a large number of countries for joint action on SLCPs. who has further underscored the importance of this linkage and action. This effort requires a more effective interface with the UNFCCC process for comprehensive mitigation measures to maximise air quality; public health and welfare gains while fast tracking CO2 reduction and building climate resilience. Focus on priority action at the COP28 and beyond should be built.
Countries are already shaping their clean air and climate programmes, policies and implementation strategies to meet clean air targets. Interlinking the learning from these programmes at local and global level and strategic support can have a multiplier effect. A growing number of countries have started to include air pollution in their reporting on nationally determined commitment (NDC) to the UNFCCC and will revise NDCs in 2025. This needs to include assessment of public-health benefits and low-carbon gains. Countries that are reporting on clean air action to capture the learning curve and promote cross learning must be engaged and convened.
Several global platforms and forums have been established alongside the cop process for more advanced action in several sectoral areas, including clean energy transition, clean cooking, and zero emissions vehicle (ZEV) transition that can be leveraged to accelerate SLCP action in different regions. Some of these platforms include the Declaration on 100 per cent transition to zero emissions by 2030-2040, the ZEV Transition Council, which represents 50 per cent of the global car market and Solar Alliance.
Global and national networks should be convened to sensitise them about SLCPs and the linkage between clean air and climate action and cross learning should be promoted. This can support local action in the Global South with science, good data and best practice approaches. There is considerable opportunity in the early stages of motorisation and industrialisation to be preventive and avoid pollution-intensive pathways. Engagement to influence global climate finance mechanism must be built and additional finance including bilateral and multilateral funding need to be unlocked and mainstreamed with appropriate indicators to assess the co-benefit outcomes from the investments.
Campaigns to improve public visibility of these issues must be designed and public and policy understanding of science, policy and action related to SLCPs deepened to help build the new narrative. This requires creative communication on good practices and innovations, to influence opinion and mobilise opinion makers and local stakeholders in different regions. Building a global database and inventory of greenhouse gases and SLCP sources and emissions must be enabled and local institutional capability be strengthened to inform action.
This article was first published in The State of India’s Environment 2024