Why do small degrees of warming matter?

Hello from a cold New York day and welcome to the AP Climate Watch newsletter. I am Natalia Gutiérrez, climate engagement manager, and today I’ll explain why fractions of a degree are critical in the problem of climate change. This information is based on our series Climate Questions. Let us know what you think.?

Scientists have confirmed what was widely expected following month after month of individual heat marks: 2023 was Earth's hottest year on record. Last week, the European climate agency Copernicus said the year was about one-sixth of a degree Celsius (about one-third degree Fahrenheit) warmer than 2022.?

What’s more, Copernicus said the year averaged 1.48 degrees Celsius (2.66 degrees Fahrenheit) above pre-industrial times. This is super close to the 1.5 degrees that countries had hoped to stay within under the 2015 Paris agreement to try to stave off the worst effects of climate change.?

That heat record was only by a sixth of a degree? Why is that such a big deal???

Well, that might not seem like much. But it actually is a pretty big margin when it comes to such measurements. And while those fractions might not be noticeable to a person, they make a big difference. Even small changes in average global temperature can turn weather wilder and more extreme.?

This might not be news for you if you remember record heat last year in North America, China and many other places – heat that sometimes killed. Then there was the lengthy drought that devastated the Horn of Africa, the torrential downpours that wiped out dams and killed thousands in Libya and the Canada wildfires that polluted the air from North America to Europe.?

All this is already happening. But if we continue along the same path and temperatures increase by about 2 degrees Celsius by the end of the century, the world will experience five times the floods, storms, drought and heat waves, according to estimates by the Intergovernmental Panel on Climate Change.?

What do scientists say??

There’s no doubt climate scientists are worried about this. AP science writer Seth Borenstein asked more than three dozen scientists what the smashed records mean. Most said they fear acceleration of climate change that is already right at the edge of the hoped-for limit agreed upon in Paris.?

“The heat over the last calendar year was a dramatic message from Mother Nature,” said University of Arizona climate scientist Katharine Jacobs.??

Nearly every scientist who responded to AP’s questions blamed greenhouse gases from the burning of fossil fuels as the largest reason the world hit temperatures that human civilization has not likely seen before. El Ni?o, the cyclical warming of Pacific Ocean waters, was the second-biggest factor, they said.

Next week we’ll talk about some of the solutions we have covered.?

Read more:?

• Climate Questions?
• Climate Questions: Why do small degrees of warming matter??
• Climate Questions: What’s going on with climate change??
• Earth shattered global heat record in ’23 and it’s flirting with warming limit, European agency says?
• Scientists explain why the record-shattering 2023 heat has them on edge. Warming may be worsening?
• Check out all our climate coverage here

Here’s what else you need to know?

?? Scientists find about a quarter-million invisible nanoplastic particles in a liter of bottled water?

?? Climate change is shrinking snowpack in many places, study shows. And it will get worse?

One big number:

$57.6 billion?

The total damage from 23 weather extreme events in America that cost at least $1 billion by September 2023, according to the National Oceanic and Atmospheric Administration.

Thank you for reading this newsletter. We’ll be back next week. For questions, suggestions or ideas please email [email protected]?

This newsletter was written by Natalia Gutiérrez, climate engagement manager, and edited by Douglas Glass ,?an editor for climate and environment.

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