By Sean Cummings
For months, climate experts have urged governments to center renewable energy and infrastructure in their economic revivals, seeing the drop in global emissions caused by the COVID-19 pandemic as a chance to transition to a greener future.
However, as we take steps to reopen, greenhouse gas emissions have quickly rebounded. Although global CO2 levels had fallen 17% from 2019 levels by early April, they’ve since climbed to just 5% below 2019 levels. Bloomberg reports roughly $509 billion in stimulus money going to the carbon economy worldwide, while low-carbon industries got only $12.3 billion.
And although the pandemic has dealt a major blow to the petroleum industries, bankrupt companies leave behind unplugged wells leaking methane—currently two million in the U.S. alone.
Recent heat waves make clear the necessity of taking this opportunity to permanently reduce global emissions. Siberia reached 100-degree temperatures and in our own south-southwest, officials must weigh social distancing requirements against the need to provide public cooling centers for heat-stricken communities.
Rising coastal flooding risks drive the point home. The National Oceanic and Atmospheric Administration shows U.S. cities in the coastal south experienced 2-3 flooding days in 2000; last year it was in the teens. NOAA projects double to triple this amount by 2030 and coastal cities flooding 25-75 days annually by 2050.
With outcomes like these, we need a green rebound from the pandemic. A recent paper in Nature Scientific Reports says our current atmospheric CO2 (415 parts per million) matches peak levels of the Pliocene, 3.3 million years ago. Then temperatures were 3-4 degrees Celsius hotter and sea level twenty meters higher. Pre-lockdown emissions rates would push us further back to levels of 15 million years ago.
Assumptions about how global climate would respond to continued emissions have remained steady for decades: a doubling of CO2 from pre-industrial levels would yield a 66% chance of global warming, averaging out to around three degrees Celsius. Recent studies estimate up to five degrees, which suggests our worst-case estimates aren’t extreme enough.
However, a more recent study estimates a smaller range (between 2.6 - 3.9 degrees Celsius). Raising the minimum end of the range to 2.6 degrees eliminates any possibility that luck will save us, undermining denialist arguments in favor of inaction, while lowering the maximum end to 3.9 degrees questions previous worst-case scenarios.
While this tighter range may lessen uncertainty, it still allows for plenty of climatic variability, much of which we already experience. A recent study in Science ranks 2000-2018 as California’s driest stretch in 1,200 years, but places 1980-1998 as the wettest.
This pattern exemplifies climate change in the state: while our average precipitation has remained relatively stable, that average comes increasingly from alternating, back-to-back extremes.
California’s precipitation also falls increasingly as rain rather than snow, replacing the slow-melting Sierra snowpack with short but intense deluges and making water capture and storage more difficult.
Locally, the reelection of Joan Hartmann has ensured Santa Barbara County a few more good steps toward mitigating these challenges. The Board of Supervisors began the two-year process in July of designing a greenhouse gas emissions reduction plan, starting with a consultant. The county aims to get to 50% below 2007 emission levels, or 675,900 tons per year, by 2030.
