Global Warming: Talk About It

From time to time I ask people a question to gauge how much they know about climate change: “What’s your best guess, how much has Earth’s average temperature changed since the year 1900?

Global Warming: How Long Do We Have Left?

It’s already bad. But when will things get so bad that it is obviously — obviously — the worst problem in the world? How long until we go over the cliff? That depends on how much we’ve heated up already, and how fast we’re getting hotter.

We have already reached dangerous levels. The heat waves throughout the northern hemisphere this summer have cost plenty, to the economy, in human suffering, ill health, even lives lost. The wildfires in California this year were much worse than they would have been without global warming. Just last year we set a new record for the total cost (adjusted for inflation) of billion-dollar climate-related disasters. They cost the U.S. over $300 billion.

As bad as it is already, extremely bad is yet to come. Some say it’ll be when total warming since pre-industrial times reaches 2°C, others say — and I agree with them, given the costs we’ve already seen — that we’ll cross that threshhold at 1.5°C. That’s the level at which the costs, both economically and in terms of human life and suffering, will threaten our ability to cope.

I am not a climate scientist

Reader “Deltaeus” expressed his frustration about many aspects of the “debate” about climate change, including the fact that there are shallow arguments all over the place. I’d like to respond to some of his comments.

Don’t Settle for Easy Answers about Global Warming

You are not a dummy. But climate deniers treat you that way.

New Prediction Paper

Some of my long-time readers have expressed an interest in a recent paper which attempts to predict how global temperature will change over the next few years, A novel probabilistic forecast system predicting anomalously warm 2018-2022 reinforcing the long-term global warming trend (Sevellec and Drijfhout 2018, Nature Communications). It has received quite a bit of publicity, featured in numerous newspaper articles, along the lines of “the next five years will be extra hot.”

Statistics: not for Cliff Mass

It all started with Cliff Mass saying “… with huge transient peaks and troughs (see below). With such variability …” when talking about CalFire data of area burned by wildfire in California from 1987 through 2016. His comment led me to make a very serious mistake: I thought he might actually know what he was talking about.

Year of Wildfires

As bad as it has been, it’s going to get worse.

Questions for Cliff Mass

In response to my post, you said my analysis is “very weak” and that I used “an inappropriate statistical approach that did not consider the variability of the time series.”

The Theil-Sen trend estimate is robust, in fact it’s what statisticians call “non-parametric” (although I prefer the name “distribution free”). Such methods are specifically designed to account for the variability of the time series. What is your basis for stating otherwise?

What method would you prefer? What method did you use?

Cliff Mass puts a brown paper bag on your doorstep … sets it on fire … and rings the doorbell

Cliff Mass has joined the ranks of those who want you to believe that California’s wildfire problem isn’t getting worse.

USA Temperature: can I sucker you?

Suppose I wanted to convince people that temperature in the USA wasn’t going up, it was going down. What would I show? Let’s try yearly average temperature in the conterminous U.S., also known as the “lower 48 states” (I’ll just call it “USA”):