Esa's Notebook

We are now increasingly concerned about climate change. This concern is partly justified, because global warming is probably a fact, not just a belief. However, climate models are extraordinarily complex.

Dr. Judith Curry is an American climatologist. According to her, no climatological catastrophe is looming. There are several factors that she points out.

Time frame

The global data of weather before 1985 is fairly weak. If you’re trying to define a trend towards cooling or warming or increased or decreased variability, the question immediately arises whether you’re talking about 100, 1000, 10 000 or a million years. There is an infinite number of time frames. The question is what time frame is justified to prove that a real change in climate has occurred.

Anthropogenic climate warming

Anthropogenic climate warming is a pretty new invention. Before 1992 there was no discussion about human caused warming at all. Then scientists became involved in this. A “social contract” between scientists and policy makers appeared, gradually dominating the discussion. Also, the career goals and the funding of scientists were involved in this complex interaction between science and policy making. The dimensions of climate models were growing and growing every year and becoming more and more complex. It is obvious that there are a lot of things that we do not understand.

Extreme weather

Until now people were not speaking about extreme weather. For example, the melting of ice caps vary from year to year with a little bit of melting, but there is no catastrophe looming on those fronts. Dr. Curry said that she was the first to put peoples head that even +1° can cause something bad like more category 5 hurricanes. So that started the whole trend where every extreme weather event was associated with human caused global warming. In the first half of the 20th century, the weather was certainly worse in North America and over much of the globe than it is now. Also, right now in the US West atmospheric river brings massive amounts of rain and snow. If you go back to the winter of 1861 and 1862, 15″ of rain fell in central California over a period of a couple of months with huge floods over a widespread area for months. Paleoclimate evidence showed that these tend to happen about every two hundred years or so. So, this is nothing unusual at all.