It was a fairly ordinary storm until it passed over the unusually hot waters of the Gulf of Mexico. In many ways, Ida was the perfect example of how climate change affects hurricanes. The biggest trend, though, is the chance of storms rapidly intensifying into major hurricanes. The amount of ocean area that is warm enough to sustain a hurricane is increasing and warm conditions occur earlier in the spring and extend later in the year. Hurricanes feed off of very warm ocean waters.

Rising temperatures also affect hurricanes, some of the costliest and deadliest weather events that we experience. Something as weird as the 2021 Northwest heatwave may be unlikely, but the climbing global temperatures ratchet up the probability of dangerously high temperatures in the U.S. With or without La Nina, we can expect to see parts of the country struggle with deadly heat this summer. But it’s expected to fade in the coming months, so 2022 has a good shot at being warmer than 2021. La Nina is like having the global air conditioner set on max - it tends to depress global temperatures. We are currently in a La Nina - a weather pattern triggered by unusually cool water in the equatorial Pacific. The year 2021 will likely be the sixth warmest on record. and the UK Met Office will soon release their final calculations of global mean temperature. The National Oceanic and Atmospheric Administration (NOAA) and NASA in the U.S. The second trend follows the first: rising temperatures. That would mean growing less than 2.4 ppm, so staying below 421 ppm. In 2021, the question is not whether we will beat 418 - we definitely will - but whether we see signs that emissions are slowing. Last year, the CO2 monitoring station in Hawaii recorded an all-time weekly high of 418 parts per million (ppm). Atmospheric CO2 reaches its annual peak in May. Humans around the world still burned tons of fossil fuels - likely adding 36.4 billion tons of carbon dioxide to the atmosphere. We all hoped that maybe the economic slowdown from the COVID-19 pandemic would blunt the rise of carbon dioxide that drives global warming and makes extreme weather more likely. The first is the big one: carbon dioxide in the atmosphere. I see six trends that can impact virtually all of us next year. But thinking about my climate work over the last year, I was struck by how much of it is about trends. It’s tempting to look back at the big stories: record cold in Texas, record heat in the Northwest, record rains from Hurricane Ida and December’s heat and deadly weather. We’re about to wrap up 2021, another year of climate extremes across the U.S.

Big weather pattern change