Luiz Galvão and Paulo Buss
Throughout history, there are many records of disasters that decimated entire populations, cities, states and civilizations. None of those had the same level that the climate change crisis foresees. UN’s secretary-general, António Guterres, stated that the report of Group I of the IPCC (Intergovernmental Panel on Climate Change) is “a code red for humanity”. The report contained compelling evidence that the gas emissions from fossil fuel combustion and deforestation are smothering the planet and endangering billions of people. Guterres also stated that the report “might sound like a death-warrant to fossil fuels, before they destroy our planet” and requested immediate action, aiming at a significant decrease in pollutant emissions, since it is the only way of limiting the increase in the global temperature to 1.5°C.
The Group I report did not surprise experts and activists, nor those who have been feeling the immediate impact of the climate change crisis. The young activist Greta Thunberg said that the text “confirms what we already know through thousands of previous studies and reports, that we are in an emergency. It is a solid but cautious summary of the best available scientific data”. She also added that the IPCC does not present any solutions and that “It is up to us to be brave and take decisions based on the scientific evidence”.
Just as the pandemic that is still not under control, the climate change crisis will reveal the iniquities caused by discrimination and systemic prejudice in an even more dramatic way. People in vulnerable position will be the ones suffering the consequences of the delay by the ones in charge in taking the necessary actions, who remain worried about advocating a status quo that may disappear faster than imagined. New unprecedented disasters will be caused by the global temperature increase of 1.5°C, that will be reached in 2030, 10 years earlier than forecasted, and that may reach 2.7°C until the end of the century, comparing to the average temperature during the pre-industrial era. The extensive report (AR6) can be seen on IPCC’s page. We present a summary of the main conclusions of the document’s four areas below.
A. The current status of the climate
A.1 It is unequivocal that human influence has warmed the atmosphere, the ocean and the land.
A.2 The scale of recent changes across the system is unprecedented over many centuries to many thousands of years
A.3 Human-induced climate change is already affecting many climate extremes in every region across the globe, which is evidenced by heatwaves, heavy precipitation, droughts, and tropical cyclones.
A.4 The knowledge of climate processes and evidences were improved, giving a best estimate comparing to the last report (AR5).
B. Possible climate futures
B.1 Global surface temperature will continue to increase until at least the mid-century, under all emissions scenarios considered.
B.2 Changes in the climate happen due to increasing global warming, and causes an increase in the frequency and intensity of climate extremes, with heatwaves, and heavy precipitation, agricultural droughts, intense tropical cyclones and reductions in the Arctic Sea’s ice.
B.3 Continuous global warming is projected to further intensify the global water cycle, increasing the intensity of wet and dry events.
B.4 Under scenarios with increasing CO2 emissions, the ocean and land carbon sinks are projected to be less effective at slowing the accumulation of CO2 in the atmosphere.
B.5 Many changes due to past and future greenhouse gases emissions are irreversible for centuries to millennia, especially changes in the ocean, ice sheets and global sea level.
C. Climate information for risk assessment and regional adaptation
C.1 Natural heat conductors and internal variability will modulate human-caused changes, especially in regional scale and on the short term, however, having little effect on centennial global warming.
C.2 With further global warming, each region might experience multiple concurrent changes.
C.3 Risk assessment should not dismiss low-likelihood outcomes, such as ice sheet collapse, abrupt ocean circulation changes and some extreme events.
D. Limiting future climate change
D.1 From a physical science perspective, limiting human-induced global warming to a specific level requires limiting cumulative CO2 emissions, reaching at least net zero CO2 emissions, along with strong reductions in other greenhouse gas emissions. Strong, rapid and sustained reductions in CH4 emissions would also limit the warming effect and would improve air quality.
D.2 In the scenarios called SSP1-1.9 and SSP1-2.6, with very low or low Greenhouse Gases (GHG) emissions, it would take years to obtain discernible effects on greenhouse gases and aerosol concentrations, and air quality, relative to high and very high GHG emissions scenarios (SSP3-7.0 or SSP5-8.5). Under these contrasting scenarios, discernible differences in trends of global surface temperature would begin to emerge from natural variability within around 20 years, and over longer time periods for many other climatic impact-drivers.
Report AR6 will also have the input of Work Group II, which will assess impacts, adaptation and vulnerability, including a chapter about health, and of Work Group III, that will analyze mitigation/attenuation measures. AR6 will be more focused on solutions, regional information and more integration among workgroups. All reports in this cycle cover the topic of cities and climate changes, that will earn a special report in 2022. More details about the meeting are available in the link: https://www.ipcc.ch/meeting-doc/ipcc-wgi-14-and-ipcc-54 and about the 6th assessment report on the link: https://www.ipcc.ch/assessment-report/ar6. This information will be important for the conference of the parties of the Climate Change Conference, that will be held in Glasgow at the end of 2021 (COP26), and for the assessment meeting of the Paris agreement, in 2023.
Climate and health
The WHO released a special report for COP26 for public consultation. Titled The Health Argument for Climate Action, the document aims at sorting healthcare arguments in favor of actions facing the climate crisis. It includes evidences and solutions that may benefit health, in actions against climate changes, and prescribes an ensemble of requests to the global health community and to the ones who formulate policies on climate changes that will be part of COP26. The report is based on the special report COP24 about health and climate changes, developed at the request of the President of the 23rd Conference of the Parties to the UNFCCC (COP23), Prime Minister Bainimarama of Fiji. The report will be available for public consultation until August 25th, 2021. All comments related to the draft report should be submitted through the online feedback form.
Science and institutions are still doing their part, we need that the people in charge in all levels and areas, including private ones, take the challenge of speeding up concrete actions that are urgent and cannot be avoided. Unlike the pandemic, this crisis cannot count on any medicine or a vaccine.
* Luiz Augusto Galvão, senior researcher at the Fiocruz'Global Health Center (CRIS/Fiocruz); Paulo Buss, coordinator of CRIS/Fiocruz.