It’s been another record-breaking summer of punishing heatwaves, droughts and fires around the world. The UK broke through heat ceilings, exceeding 40 degrees Celsius (104 degrees Fahrenheit) for the first time on record. In the past four months, over 7,000 daily temperature records have been broken in places across the United States.
Wildfires and crushing heat have stretched electricity grids to the breaking point, leaving people sweltering. Historic drought in the western U.S., Europe and Asia has exposed sunken ships and archeological remains. It also curtailed hydropower in China and nuclear power in France, leading to homes losing electricity when they need cooling the most — and even revived undesired coal utility plants.
However, fires and drought somewhere mean that excess water is being shifted somewhere else. Climate change is redistributing more intense rainfall in some places and less in others. Normally arid Pakistan is experiencing unprecedented flooding, affecting 33 million people and over one-fifth of the country’s cropland. Excess monsoon rain and snow runoff from its mountains, following earlier summer heatwaves are overwhelming local infrastructure. Flash floods have also happened elsewhere, such in as the recent Kentucky tragedy.
The seemingly counterintuitive contrast of drought and flood — sometimes in the same place in the same season — is no surprise to climate scientists. Scores of studies have shown that a warmer world is prone to more intermittent, but also more extreme, rainfall (“when it rains, it pours, and pours, and pours”). This shift to a smaller number of more intense rainfall events leads to more flooding, especially when they hit degraded land that is less able to absorb water and slow its runoff.
Many of the extremes in a single season can be linked to the natural swing of El Niño and La Niña, two phases of the El Niño Southern Oscillation (ENSO), the fluctuating wind and ocean temperature pattern in the equatorial Pacific that has ripple effects on weather around the world. We are now in a La Niña phase for the third year in a row — the first such “triple dip” this century. Generally, this phase leads to a dip in global mean temperature, while driving large regional shifts in weather patterns like we’ve been seeing this year.
The coming European winter is predicted to be milder, relieving some energy security concerns, but the hurricane season is projected to be above average. Although the season started quietly, in the past week Hurricane Fiona has devastated several Caribbean islands, while Typhoon Nanmadol has pounded Japan and Typhoon Merbok has hit parts of Alaska. The swing back to El Niño in the next couple of years will bring other unprecedented phenomena, stressing different locations and communities.
Some of these regional weather anomalies can be attributed to natural ENSO variability, but the severity of the extremes poses the question: How much is global warming loading the dice? Advances in climate modeling are allowing fast attribution of individual extreme events, including the role of global warming in increasing rainfall intensity in Pakistan. This has helped raise public awareness of climate change by making ongoing events teachable moments, and may soon be used in climate litigation.
The news and public perception fix on the climate disasters unfolding right before us, but scientists are more concerned about less reported changes, such as accelerating increases in methane concentration in the atmosphere due partly to warmer wetlands pumping out more of the gas, to soot injection from wildfires damaging ozone layer, and to diminishing reflective Arctic and Greenland ice and the associated disruption to atmospheric circulation.
Such self-reinforcing feedbacks amplify human-caused warming. Earlier this month, researchers published an alarming assessment of tipping points in the climate system, identifying six at risk of being triggered when we pass 1.5 degrees Celsius and head towards 2 degrees Celsius above pre-industrial temperatures. For example, the overturning circulation of the Atlantic Ocean shows signs of tipping into a weaker state: this could disrupt the existing ENSO cycle and the associated global weather patterns with potentially devastating consequences. Currently at around an 1.2 degrees Celsius increase, we are likely to exceed 1.5 degrees Celsius within 10 years: indeed, there is even a 10 percent chance that the average over the next five years could exceed this guardrail.
Many assessments have shown that every fraction of a degree of warming brings more severe impacts. The rate of warming also matters. If it’s too fast, it not only risks triggering tipping points sooner, but impedes the capacity of natural and human systems to adapt.
So, we must win two races against climate catastrophe: a sprint to slow warming as fast as possible over the next decade or two — and a simultaneous marathon to phase out fossil fuels and shift to clean energy.
A new law, Inflation Reduction Act, is an important boost in both these races. It provides much-needed policy certainty for the decarbonization marathon, including scaling up low carbon and renewable power and adopting energy efficient heat pumps. At the same time, it drives the near-term sprint by penalizing wasteful methane emissions from the oil and gas sector.
It’s already too hot. Soon it will also be too late. The Biden administration and states like California are speeding up solutions to the climate emergency. The rest of the world must do the same.
Yangyang Xu, Ph.D., is an associate professor in the Department of Atmospheric Sciences at Texas A&M University.
Gabrielle Dreyfus, Ph.D., is chief scientist at IGSD and an adjunct professor at Georgetown University.
Durwood Zaelke is president of the Institute for Governance & Sustainable Development (IGSD) in Washington, D.C. and Paris, as well as an adjunct professor, University of California, Santa Barbara Bren School of Environmental Science & Management.