Issue 3: The IPCC Report

August 9th was a momentous day for our warming world. On this day approximately one month ago, the Intergovernmental Panel on Climate Change (IPCC) of the United Nations released a long-awaited report summarizing more than 14,000 studies on the physical science of climate change, and what that means for our future. In this newsletter, we synthesize the main takeaways and offer tools for action.
Image: IPCC Report
Five takeaways:

  • “It is unequivocal that human influence has warmed the atmosphere, ocean and land”. This is the first IPCC report to explicitly state that without a doubt, humans are responsible for the 1.1 degrees C of global warming to date. Ironically, some human activities are also leading to cooling via aerosols, partially masking the true warming effect of anthropogenic greenhouse gases. Without these aerosols, we would likely already be at 1.5 degrees C of warming.

  • This degree of climate change, and the rate of change, is unprecedented throughout known history. The report finds that in 2019, CO2 concentrations were higher than at any time in at least 2 million years. Temperatures in the most recent decade were greater than any decade in at least 125,000 years. There has not been a time in at least the last 1500 years when the Arctic sea ice area was as small as it now. And these extremes are happening quickly—global mean sea level has risen faster in the last century than any preceding century in at least 3000 years.

  • Human-induced climate change is already leading to extreme weather events in every region of the world. With record-breaking extreme weather events including Hurricane Ida and California wildfires just in the past month, it likely comes as no surprise that heatwaves, heavy precipitation events, droughts, tropical cyclones, and compound extreme events are already increasing in frequency and intensity due to climate change. And as we will continue to cover in our newsletters, all of these have devastating health impacts.

  • No matter what emissions-reducing actions we take starting today, we are locked into 30 years of worsening climate impacts. Earth has already warmed approximately 1.1 degrees Celsius. Because greenhouse gas emissions have a cumulative effect, even if we were to sharply cut emissions right now (highly unlikely), global warming will continue until mid-century, with essentially guaranteed worsening of the extreme weather events we are already seeing. And some impacts will continue for far longer- for example, sea level will continue to rise for at least 2000 years.

  • There is still (a small) window for us to save our future. And every ton counts. The Paris Climate Agreement sets 1.5 degrees of warming as a “tipping point” beyond which further warming would be truly catastrophic. There are five possible climate futures outlined in the IPCC report corresponding to various emission levels (see below). All scenarios basically get us to 1.5 degrees by 2040. But beyond that, the futures diverge drastically; if the world does nothing to curb emissions, temperatures by 2100 could be 3-6 degrees Celsius warmer than preindustrial levels.
Learn More

To learn more about the IPCC report and its implications, as well as climate change more generally, check out the following resources:
Take Action

Though the IPCC report is a necessary wake-up call, all hope is not lost. We find motivation in the following framing: climate change is not like nuclear war. It is not all or nothing. There are infinite possible futures and every 0.01 degrees counts. Even though averting climate change is dependent on collective action, if your individual actions can mitigate a small fraction of further warming, that translates into lives saved. And while fossil fuel companies have pursued aggressive marketing campaigns to frame carbon emissions as the responsibility of individual consumers, what we really need is sweeping policy change and a pervasive culture shift. Take action to sow the seeds of a healthier future:

Do you have other resources you use to learn about climate change and solutions, action items that you’d like us to share, feedback or ideas for our newsletter? Please share them here!
This newsletter was created by Karly Hampshire, Sigal Maya, Lawrence Huang, and Simona Martin, and edited by Sheri Weiser, Arianne Teherani, Jennifer Zakaras, and Naomi Beyeler, on behalf of the UC Center for Climate, Health, and Equity.