Climate science: models versus measurements

When you study the actual measured data and the CMIP computer model projections it becomes clear that carbon dioxide (CO₂) has a relatively insignificant effect that no one has quantified accurately despite all the protestations that the science is settled. The IPCC AR5 reports (2013) demonstrated how much the computer model projections (RCPs) over-inflate temperature compared to measurements. Despite the obviously inaccurate projections, the RCP8.5 scenario—the most dire and unrealistic projection—is the one most quoted by climate alarmists and referenced in climate papers.

See a more recent comparison of models to measurements here. According to measurements, even as global "action" on climate change is virtually non-existent, and what little there is has no meaningful effect on global temperature, the most realistic projection appears to be RCP2.6, which is the most benign. Natural climate variation and the theorized effects of Milankovitch cycles seem to dominate, but the science is far from understood because the global climate system is complex, non-linear, and chaotic.

see: Milankovitch cycles (Wikipedia)

Over the last million years the earth has cycled repeatedly through cold glacial periods and warm interglacial periods lasting approximately 100,000 years. We are in the warmest phase of the latest interglacial period that started about 12,000 years ago as the mile-thick glaciers covering most of the upper Northern Hemisphere began to melt, yet sea levels are still several meters lower than at the peak of the prior interglacial 125,000 years ago. All completely (or perhaps mostly) natural.

see: Sea Level Rise, After the Ice Melted and Today (NASA GISS, January 2007)

As the planet warms, life flourishes, and carbon locked up in the earth and seas begins to escape into the atmosphere, as it has several times before. Then a glacial period reverses the trend. After recovering from the Little Ice Age which ended in the mid-1800's, we are living in a serendipitously balmy period, ideally suited to life, but a lot of people are unhappy about it.

see: Holocene Temperature Variations (Wikipedia)

see: Little Ice Age (Wikipedia)

Human CO₂ emissions undoubtedly are adding to the buildup in the atmosphere, but the amount of warming theorized by physics is negligible and logarithmic. That means it takes a doubling of CO₂ to theoretically raise temperature by 1° C. The pre-industrial CO₂ concentration is estimated to be about 280 ppm. We are just above 400 ppm, nowhere close to double yet.

see: Global Monthly Mean CO₂ (NOAA ESRL)

According to statistical analysis of instrument data, global average temperature has risen about 1° C since the late 1800's and has slowed over the last 2 decades. Most of that temperature increase is natural. Roughly half occurred before the 1970's. That paltry 1° C is the temperature difference between ground level and 330 feet higher. Negligible.

see: Global Temperature Report (UAH)

Global temperature as of February 2022

And global sea level rise is approximately 3 mm per year (measured by satellites; tide gauges show less) and has actually slowed slightly in the last few years, despite all the hue and cry about Greenland and Antarctic glacier melt.

see: Global Mean Sea Level Time Series (University of Colorado)

Incidentally, sea level rise varies by location. Marshy river deltas experience more due to land subsidence. In high northern latitudes sea level is actually going down due to post-glacial rebound after all those heavy mile-thick glaciers melted and the land rose.

Tide gauge sea level trends

Check your favorite seaside vacation spot here:

see: Sea Level Trends (NOAA Tides & Currents)

Based on actual measurements, not over-inflated computer models and all the wild claims made based on the models, it's easy to see that global warming hysteria is just that: hysteria. Have a look for yourself and don't worry, be happy.