Give us your climate predictions, Andy May

Every so often WUWT publishes what it describes as "failed climate predictions". It is often timed to distract from more bad climate news, such as the fact that last year there was a record increase in the annual rise in atmospheric CO2.

The list published today, from Andy May at WUWT, follows the normal pattern. It takes a bunch of statements that were published at various times, including several from 27 years ago, and claims they are failed predictions. This includes statements that refer to things that may happen by 2100.

Yep, science deniers tend to oscillate between living in the past and living way ahead in the future. Tim Ball, one of Anthony's pet conspiracy theorists, rarely manages to emerge beyond 1970. Andy May (and Anthony Watts) both implicitly claim they have a time machine that has taken them into the future.

There are two other points worth making before I give you some examples of the low regard they (rightly) hold for WUWT fans. (They know they are a the dullest of the dim-witted.)

1. How often have they published a list of all the climate science predictions that have held up over time? Not once, to my knowledge, has WUWT published a list showing things like, temperatures will continue to rise while we keep burning fossil fuels, or seas will continue to rise, ice will continue to melt and so on. All of which is happening.
2. Nor, to my knowledge, have they bothered to publish a list of all the ridiculous failed predictions of deniers. It is common for deniers to predict a coming ice age, that the world is about to cool down, that the communists are about to take all our money and property and throw us all in concentration camps, and that we're about to enter another Maunder minimum and freeze to death. All failed predictions so far.

Now Andy boldly states up the top of his list that:

To qualify for this list, the prediction must have failed. Alternatively, it is also considered a failure when so much of the allowed time has passed that a drastic and improbable change in the rate of change is required for it to be true. 

His list doesn't pass his own test. Here is an example of Andy May's uncritical denial of science (which he credits to someone called Javier). This is the very first item in his list, so you can imagine what the rest of them are like.

1990 IPCC FAR: “Under the IPCC ‘Business as Usual’ emissions of greenhouse gases the average rate of increase of global mean temperature during the next century is estimated to be 0.3°C per decade (with an uncertainty range of 0.2°C – 0.5°C).” See here, page xi.

Points to note:

1. The estimate is for the next century (now this century), not the first 17 years of what was then the "next century". Andy is short a whole 83 years.
2. The limits of the estimate, including uncertainty, are from 0.2 to 0.5 C (See comment from William Connolley below.) are from 0.1 C to 0.8 C a decade, which is a rather large margin and the observed increase lies well within this range. 
3. The estimate is 0.3 °C per decade. Since the beginning of this century, if you just compare the two years 2000 and 2016, the temperature has increased by 0.6 °C (an anomaly of 0.4 °C for 2000 to 1.0 °C for 2016), and that's only over 17 years. That would be higher than 0.3 C a decade. If you take a linear trend from 2000 to now, the trend is 0.2 C a decade. This is well within the uncertainty range predicted under the scenario chosen by Andy May.

   

   Data source: GISS NASA

4. The scenario Andy chose, from the three scenarios included in the first IPCC report is the wrong one. It assumes a higher rate of CO2 growth than has actually occurred. In Section 5.4 of FAR, it states that Scenario A assumes a doubling of CO2 over pre-industrial levels by 2020. That is, instead of CO2 being, say, 418 to 420 ppm by 2020, which is around what would be expected based on current levels, it assumes 560 ppm. If Andy was not trying so hard to please WUWT deniers, he would have compared observations to Scenario B, which included an emissions growth closer to what has happened. That prediction was 0.2 C a decade, which is the rate that has been observed for this century so far.

In other words, even back 27 years ago, and despite all the caveats the scientists put on their predictions at the time, the scientific estimates have turned out to be remarkably close to what has been observed so far.

Deniers at WUWT are unable to understand science, unwilling to try to learn about it, and resolved to deceive whoever is willing to be hoodwinked - that's as bad a combination as you can get in a human being.

I don't have the time, and I don't expect you have the patience, to bother with the rest of his not failed predictions. With a couple of exceptions where he singled out people who got a bit over-excited about declining Arctic sea ice, his list is an out and out failure. Either he's complaining that what was predicted by the end of the 21st century hasn't happened yet, or he's misrepresenting what has already happened.

My challenge to Andy May is to:

• Make your own prediction for, say, the coming decade. Hopefully I'll still be around in 2027 to check how it goes.
• Compile a list of predictions made by deniers, which prove that climate science is a hoax, and
• Compile a list of predictions made by scientists, which are coming to pass.