WUWT Contest Winner, General Audience, 1st Place – “Is there really a climate crisis?” – Is it good?

CM Compton

My discussion will focus on two ideas. First, although global temperatures have increased since the beginning of the 20th century, the current temperature regime is not unusual compared to the past. Second, despite media reports to the contrary, catastrophically high temperatures in the coming decades are unlikely.

Let’s start discussing how our climate has changed over the years. We know the earth has had periodic ice ages lasting up to 100,000 years or more with warmer interglacial periods in between. Here’s a chart from the Utah Geological Survey showing the cycle over the past 450,000 years.

That last sharp rise on the right side of the graph shows the end of the most recent ice age known as the Wisconsin Glaciation in North America. The temperature change from the bottom to the top of the cycle averages about 20 degrees Fahrenheit.

Here are a few comments. First, it looks like the ice ages are getting longer. Second, the current mid-glacial is about eight degrees colder than the maximum temperature of the ice before it. And finally, if we take a closer look between the current glacials, what do we see?

About 5 to 10 thousand years ago, it was about 2 degrees warmer than now. That period is called the Holocene Climatic Optimum.

Now let’s take a closer look at the past 10,000 years. Here’s a chart presented in 2013 by ARD, the German version of BBC, or our own PBS:

In this graph we see that there are actually two Holocene Optima that appeared between four thousand and eight thousand years ago. After the Holocene Optima, there were cyclical fluctuations of warmer and colder periods – including the Roman Warm Period, the Medieval Warm Period, the Little Ice Age, and the current warming that began around circa year 1850.

No doubt the earth has warmed since 1850, but that was after the Little Ice Age, so I think the warming has been welcomed. And from the ARD graph, it is clear that there were three periods of relative warming before our current warming, and the current warming period is capped by two Holocene temperature peaks.

In summary, I consider there is compelling evidence that the current temperature regime is not unusual by historical standards. This is a good start, but we need more information to make policy decisions related to climate change.

What about warming since the early 20th century? Take a look at some passages from Today’s weather. This textbook provides an excellent perspective on the evolution of climatology as the first edition was published in 1982 and the most recent 13th edition came out earlier this year. This quote is from the Sixth Edition, published in 2000:

Indeed, because the interaction between the earth and its atmosphere is so complex, it is difficult to show unequivocally that the recent warming trend is mainly due to increasing concentrations of greenhouse gases. The problem is that any anthropogenic climate change signal is based on natural climate variations (“noise”) such as the El Niño-Southern oscillation (ENSO). Furthermore, in temperature observations, it is difficult to separate a signal from the noise of natural climate variability.

Note the dovish stance on recent warming. Note that

The authors of this text do not say “Science has settled down.” Far away from it. Everything changed when the Seventh Edition was published in 2003. In the chapter on climate change, the authors included the famous hockey stick chart, turning the Medieval Warm Period and the Ice Age. reduced to a prolonged period of decline, followed by record high temperatures not seen in a thousand years:

This chart, which also appears in the Third Annual Report of the Intergovernmental Panel on Climate Change, has become highly controversial. Indeed, in February 2005, an article was published on Geophysical research letterpublished by the American Geophysical Union, concluded the following:

However, it was not previously noted that, prior to the principal components (PC) analysis on the tree ring network, they performed an anomalous data transformation that strongly affected the resulting PCs.

Their method, when tested on persistent red noise, almost always produces a hockey stick with the first principal component shape (PC1) and exaggerates the eigen value first.

Pretty cool, isn’t it? Put in almost random data and no problem it will be transformed into a hockey stick.

I will go back to the Seventh Edition of Today’s weatherpublished in 2003. The authors talk about a variety of possible reasons for climate change, such as feedback mechanisms, plate tectonics, earth orbit, atmospheric aerosols, volcanic eruptions and variations in solar output.

They also wondered why the climate started to get cold after 1940 and what caused “especially cold winters in the 14th and 19th centuries”. They also continue as they did in previous versions:

… It is important to realize that the interactions between the earth and its atmosphere are so complex that it is difficult to define unambiguously. demonstrate that the warming trend over the past 100 years is mainly due to increasing concentrations of greenhouse gases. The problem is that any anthropogenic climate change signal is superimposed on a background of natural climate variations (“noise”), such as the El Niño-Southern Oscillation (ENSO) phenomenon. . Furthermore, in temperature observations, it is difficult to separate a signal from the noise of natural climate variability.

However, today’s more sophisticated climate models are much better able to filter out this noise, while taking into account both natural and anthropogenic forcings.

It seems the authors wanted it both ways. In the end, however, they delayed the climate models with quotes from the third IPCC report:

Based on the new evidence and taking into account the remaining uncertainties, most of the warming observed over the past 50 years can be attributed to increases in greenhouse gas concentrations.

Note that you know, in IPCC terms, “likely” means a greater than 66% chance.

How can non-scientists evaluate “complex climate models?” One way is to compare their predictions with actual outcomes. According to the Seventh Edition of Today’s weather published in 2003, climate models forecast a temperature increase of 1.4°C to 5.8°C between 1990 and 2100. As it turns out, the actual rate of temperature change globally as of mid-2021 is a bit under the bottom head within the expected range.

Here is another graph of data from NOAA showing that the rate of change in temperature in the United States has been near zero in the time since the 2003 edition of the Today’s weather published, published:

So what we’re seeing is little or no temperature increase in the United States over the past fifteen years, which is consistent with other unbiased regional temperature data. Furthermore, the lack of an uptrend is probably no coincidence.

Here’s an interesting chart:

Do you remember that we talked about climate models forecasting global temperature increases from 1.4°C to 5.8°C in the 2003 edition of the Today’s weather?

Well, published estimates of the effects of increasing carbon dioxide levels have declined since then.

So what should a policymaker do? Since estimates of global temperature sensitivity to increases in carbon dioxide concentrations have fallen sharply over the past 15 years, also, considering that global temperatures may not change significantly, and finally, since current temperature mode

no wonder compared to previous regimes, I consider extreme responses to any perceived threat from our changing climate to be unwarranted.

The policies suggested by the catastrophic global warming mob would cost the United States jobs. Their solutions will not change our climate in a meaningful way. In short, if we follow their lead, we will be poorer, and lower economic output will hurt the most vulnerable among us.

We don’t need to lay off people in Pennsylvania, West Virginia and South

Dakota. We don’t have to cut energy exploration in Alaska or cancel new pipelines. A reckless push towards “net zero emissions” will only make us poorer and less secure.

What we should do is encourage research and development in the energy industry. We should continue to work on clean coal, and in cleaner ways to burn oil and natural gas. We should invest in nuclear power and hydrogen as an energy source. And, yes, we should continue to research renewable energy. If someone could solve the problem of continuity – i.e. come up with a clean and efficient way to store energy – then renewables like solar and wind would become much more valuable to the public. we.

In short, encouraging the energy industry to innovate will lead to a prosperous, clean, and safe environment not only for us in the United States but for the world as a whole.