Answer to a Reader's Questions About Global Warming

Reader "AVK45" posted excellent questions to my most recent comments about President Obama's climate change remarks.

But my question is this:

What convinces you that a 1980-1998 type trend won't follow the trend of the past 15 years, which looks awfully similar to 1940-1980? If 1980-98 happened again, what convinces you that we could stop the warming in time? This question is important because the 1940-80 and 1998 through present trends did little to change the overall trend since the late 1800's and the biggest threat from a warmer planet would be sea level rise, not more frequent storms.

To begin, please take a look at this annotated graph of world temperatures since 1950. I'm going to take his/her questions one at at time:

• What convinces you that a 1980-1998 type trend won't follow the trend of the past 15 years, which looks awfully similar to 1940-1980? 

You are correct, the current pause/stoppage of global warming does look like cooling during the middle of the 20th Century. But, I suggest you widen your view of the graph.  

Look at the rise from 1910 to 1944. The earth was coming out of the Little Ice Age. Temperatures would be expected to warm without mankind's contribution, but how much? No one knows. 

Climate scientists generally believe human-caused warming began in the 1950s. OK, let's accept that. Now, take a look at the size of the warmup from 1910 to 1944 and from 1979 to 1998. About the same magnitude aren't they? If the early 20th Century warming had continued without the mid-century cooling, temperatures would have followed the blue arrow and the rise would have been about double just by continuing the "natural" trend (red dot at end of arrow).   

Now, to be clear, I'm not saying that would have happened. But, climate science can't explain the mid-century cooling. Human? Natural? Both? We don't know. And it isn't like I haven't asked (see comments section here, which is just the most recent time)! So, Mother Nature has proven she can create warmups of the same magnitude of 1979-1998 all by herself. We also know that around 1000 AD earth was warmer than it is now, so a warmup of that magnitude is possible without human greenhouse gases contributing.  

For me, the real question is why did the climate cool in the mid-20th Century?

• If 1980-98 happened again, what convinces you that we could stop the warming in time?

To me, there is nothing ominous about that warmup. To the contrary, it was a wonderful thing for humanity! Between the "green revolution" and the warmup, the huge famines of the '60s and '70s stopped! In fact, there is much more food production today, per capita, then there was 40 years ago.

The battle to feed humanity is over...

                [so began Paul Ehrlich's book, The Population Bomb, 1968.]

Ehrlich couldn't have been more wrong because he assumed temperatures would remain stable.

U.N. graph showing crop production (orange) has risen  in spite of what are supposed to be temperatures that are too high for the world. 

A global cooling of any significance would be catastrophic for humanity because the shortened growing seasons would mean we would not be able to handle the now much larger population of earth.

As to whether we could "stop the warming in time," I'm confident we could not. But, it is not clear to me that more warming is the net major problem the global warming industry says that it is.

• This question is important because the 1940-80 and 1998 through present trends did little to change the overall trend since the late 1800's and the biggest threat from a warmer planet would be sea level rise, not more frequent storms.

I completely agree this is important but I don't fully accept the premise of the question which is that sea levels started rising with human global warming. Here is the long-term sea level graph from the University of Colorado. For a quarter-century we have been told we were going to see an acceleration in the rate of increase of sea level. See an increase? I don't.

There was a big increase in the rate of sea level rise from about 1937 to 1951 and it has slowed down a bit since. So, when it comes to sea level, it is rising at about the same rate regardless of what humans do.

I agree that there is some level of threat from higher sea levels. But, there is a lot we can do to mitigate and adapt which is far, far, far less expensive than $10 trillion "let's pull the CO2 out of the atmosphere"-type schemes and getting our energy from unreliable wind power.

There is a small, but growing, number of scientists that believe the next significant move in temperatures will be down rather than up. Spending money, right now, to "stop global warming" -- which has already stopped on its own -- will be counterproductive if the real problem is cooling. That is why I am completely sanguine about waiting two years (that's all) to see if the cooling materializes. Temperatures are already well below the global warming industry's forecasts which has bought us time.

I'll restate something I've said on this blog a number of times: If temperatures rise significantly over the next two years in face of the forecasts of cooling, then I'll agree measures will be needed. For now, we can wait.

Thanks again for the questions.