With the release of a third installment on April 4, 2022, the Intergovernmental Panel on Climate Change has officially wrapped up its Sixth Assessment Report. This report drew on tens of thousands of academic papers in the climate space, serving as a summary for policymakers, journalists, and the public on the state of climate change today. Each of the three installments was penned by a working group of more than 200 authors in various academic fields from all parts of the world.
Here are six key takeaways from the IPCC’s Sixth Assessment Report:
1 Climate change is here right now.
Global surface temperatures have warmed 1.1°C since preindustrial times due to anthropogenic greenhouse gas emissions. Extreme weather events — heat waves, heavy precipitation, droughts, and tropical cyclones — have become more frequent and more severe. Since the release of the Fifth Assessment Report in 2014, scientists have begun to establish a cause-effect relationship between climate change and certain extreme events such as heat waves and hurricanes. Climate change has also led to water scarcity, food shortages and price spikes, severe impacts for the farming and fishing livelihoods, mass species extinctions, mass coral bleaching, mass ice melt, and decline in trees and carbon storage from tropical rainforests. Lohachara Island and Purbasha Island are already submerged due to rising sea levels. The saying “Climate change is a problem for our children and grandchildren” still holds true. But it is also a problem right here and now.
2 As warming continues, positive feedback loops become more extreme.
In environmental science, a positive feedback loop refers to a system with one variable increasing the occurrence of another variable which, in turn, increases the occurrence of the first variable. Working Group I shows that out-of-control climate change triggers a cascade of positive feedback loops. A warmer climate leads to increased use of air conditioners. These emit greenhouse gases that trap more heat in the atmosphere. A warmer climate increases the incidence of wildfires. A burning forest releases stored carbon dioxide, which further warms the climate. A warmer climate leads to the melting of the polar ice caps. These are reflective surfaces. As they decrease in area, less solar radiation is reflected out of the atmosphere and more is left to be absorbed, thus warming the planet. And the list goes on.
3 For each half-degree of warming, climate adaptation options become less appealing.
Experts agree that solutions designed to adapt to climate change are as important as solutions designed to reduce greenhouse gas emissions and mitigate global warming. Many adaptations still feasible today can potentially help with environmental, economic, health, and socioeconomic concerns. Clean water, food security, and more reliable energy help reduce poverty. Green buildings, greenspaces, clean water, clean energy, and better transportation help human health. Protecting mangroves, reefs, seagrass, and coastal ecosystems provides protection from flooding and tropical storms, as well as removing carbon from the atmosphere and preserving biodiversity. So climate adaptation can turn into what the report calls climate resilient development: adapting to climate change while developing the economy and working at other important goals.
When global warming tops 1.5°C, many projected adaptations are no longer possible. Coral reefs can’t adapt, outdoor labor in some regions can’t adapt, travel and tourism patterns change, water shortages compel human migration, and many more species fall into extinction. Working Group II examines the growing difficulty of adaptation with each additional increment of warming. At 1.1°C, a community living in an island country might build seawalls. At 1.5°C, they might have to move inland. At 1.1°C, a farmer might plant shade trees for protection from heat. At 1.5°C, the farmer might have to abandon farming and move to the city.
4 Reducing greenhouse gas emissions helps the economy.
Working Group III analyzed the costs and benefits of climate mitigation strategies aimed at reducing greenhouse gas emissions, and found some promising results. In the past decade, the cost of photovoltaic solar dropped by 85 percent, the cost of onshore wind dropped by 55 percent, and the cost of batteries for electric vehicles dropped by 85 percent, bringing these energy sources close to parity with fossil fuel alternatives.
On top of that, an analysis of 38 climate solutions found 16 that are cost-saving measures from the outset (e.g. wind, solar, nuclear, efficient lighting and appliances, public transit), and another 13 that cost less than $20 for every ton of CO2 emissions eliminated (e.g. hydropower, geothermal, better agriculture practices, better forest management). Even these solutions, which involve some up-front cost, will save incalculable amounts in the long view, when compared to the costs of storm, flood and fire damage; mass human migration; medical treatment for mosquito-borne illness; and a long list of other consequences of uncontrolled climate change.
5 Climate action doesn’t have to be “balanced” with other important issues.
In addition to demonstrating the cost-effectiveness of climate solutions, Working Group III also ranked 43 climate solutions against the United Nations Sustainable Development Goals (SDGs). In 2020 the U.N. released a list of 17 goals to create a better future for all — among them an end to poverty and hunger; better education; gender equality; clean water; economic growth; innovation; and world peace. Working Group III made a table with 16 SDGs as the columns, and 43 climate solutions as the rows. For each combination, the table shows a plus if the two had synergies, a minus if there would be trade-offs between the two, and a dot if there were a mix of synergies and trade-offs.
Out of 396 combinations, there were 271 plusses, 113 dots, and 12 minuses. In only twelve out of 396 instances, then, were there clashes between a climate solution and another global issue. In an overwhelming majority of cases, a climate solution was shown also to be a help to an essential SDG.
6 The global community has made progress. But it needs to move faster.
Global greenhouse gas emissions are currently at an all-time high of 59 billion tons per year. From 2000 to 2009, emissions grew on average by 2.1 percent per year. From 2010 to 2019, emissions grew on average by only 1.3 percent per year. This modest gain shows that the world has begun the process of “flattening the curve.” In 2015, the world was on track to warm by nearly 4°C by 2100. Thanks to clean energy growth and better policy, this projection has now been moderated to about 3°C by 2100. Working Group III demonstrates that this rate of progress, while significant, needs to be accelerated in order to prevent environmental catastrophe.
To achieve the internationally agreed-upon goal of limiting global warming to 1.5°C by the end of the century, Working Group III proposes the following benchmarks: peak global emissions in 2025, cut emissions by 43% by the early 2030s, and achieve carbon neutrality by the early 2050s. The report shows these benchmarks to be economically feasible as well as beneficial, and it includes a comprehensive list of policies that might be used to implement the 43 climate solutions referenced above.
Above all else, the IPCC report is a progress report on climate action. The problems remain serious. To meet agreed-upon targets, curb the worst possible impacts of climate change, and address a long list of critical issues, now is the time for the global community to pick up the pace on climate action.