Global warming

Imagine a future where, despite efforts to reduce greenhouse gas emissions quickly, parts of the world have become unbearably hot. Some governments might decide to “geoengineer” the planet by spraying substances into the upper atmosphere to form fine reflective aerosols – a process known as stratospheric aerosol injection. Theoretically, those tiny particles would reflect a little more sunlight back to space, dampening the effects of global warming. Some people envision it having the effect of a volcanic eruption, like Mount Pinatubo in 1991, which cooled the planet by about half a degree Celsius on average for many months. However, like that eruption, the effects could vary widely across the surface of the globe. How quickly might you expect to notice your local temperatures falling? One year? Five years? Ten years? What if your local temperatures seem to be going up? As it turns out, that is exactly what could happen. While modeling studies show that strato...

There’s an old joke about the fellow who has his left foot in a bucket of ice water and the right in a bucket of hot water, so that his overall temperature is average. That seemed to apply to the climate during 2022’s northern summer of extremes. Global warming is undoubtedly a factor, but just how the increasing extremes – heat waves, droughts and floods, sometimes one on top of the other – are related can be bewildering to the public and policymakers. As a climate scientist, I’ve been working on these issues for more than four decades, and my new book, “The changing flow of energy through the climate system,” details the causes, feedbacks and impacts. Let’s take a closer look at how climate change and natural weather patterns like La Niña influence what we’re seeing around the world today. The June-August 2022 global land and ocean surface temperature was 1.6 degrees Fahrenheit...