By Seanna Watson
In late September, a group of 500 “prominent scientists and professionals” sent a letter to the UN Secretary-General declaring that there is no climate emergency .
Several science groups have followed up on this. The Climate Feedback website provides an extensive scientific analysis . In summary, they found the scientific credibility of these claims to be low, characterizing the article as “biased, cherry-picking, inaccurate, misleading.”
The declaration made six main points:
1) Nature as well as anthropogenic factors cause warming.
One might argue about the relative contribution of anthropogenic vs natural factors, but this does not negate the fact of climate change, or the requirement to do what we can to reduce the human-caused component, as well as to prepare for mitigation of the effects.
2) Warming is far slower than predicted.
On the contrary: Warming is, in many cases, faster than had been predicted, as highlighted in a recent paper : “On average across Europe the number of days with extreme heat and heat stress has more than tripled and hot extremes have warmed by 2.3°C from the year 1950 to 2018. Over Central Europe, the warming exceeds the corresponding summer mean warming by 50 percent. Days with extreme cold temperatures have decreased by a factor of 2 to 3 and warmed by more than 3°C, regionally substantially more than global winter mean temperatures. Cold and hot extremes have warmed at about 94 percent of stations, a climate change signal that cannot be explained by internal variability.”
3) Climate policy relies on inadequate models.
In fact, as pointed out by research scientist Twila Moon , the basic chemistry and physics of climate change and the greenhouse effect have been well understood for more than a century:
- 1859 – John Tyndall discovers that some gases block infrared radiation. He suggests that changes in the concentration of the gases could bring climate change.
- 1896 – Svante Arrhenius publishes the first calculation of global warming from human emissions of CO2: Doubling the CO2 in the atmosphere would raise the global temperature by some 5–6°C (9–11°F).
- 1897 – Thomas Chamberlin produces a model for global carbon exchange including feedbacks.
- 1938 – Guy Callendar argues that CO2 greenhouse global warming is underway, reviving interest in the question.
- 1960s – Charles Keeling accurately measures CO2 in the Earth’s atmosphere and detects an annual rise. The level is 315 ppm. Suki Manabe and Richard Wetherald make a convincing calculation that doubling CO2 would raise world temperatures a couple of degrees.
- 1977 – Scientific opinion tends to converge on global warming, not cooling, as the chief climate risk in the 21st century.
4) Carbon dioxide is plant food, the basis of all life on Earth.
The dose makes the poison. For example, water is also essential for life, but too much of it in the wrong place can be deadly. And some recent studies of the effects of increased atmospheric carbon dioxide on plant growth have yielded unexpected results — the improvement in growth was significantly less than predicted (which also means that the optimistic view of how much plants will be able to reduce the levels of CO 2 in the atmosphere needs to be revised).
5) Global warming has not increased natural disasters.
On the contrary, weather-related natural disasters have increased, both in North America and Europe .
6) Climate policy must respect scientific and economic realities.
The scientific reality is that the climate is changing. The economic reality is that if we don’t spend the money to take action soon, we will certainly pay much more later.
It’s also worth noting that a tiny minority (10) of the 500 signatories are climate scientists. Most of the scientists are physicists and chemists and geologists, and the group also includes engineers and health care professionals, as well as economists, architects, journalists, and business professionals. They may very well be competent experts in their own fields, but this group as a whole is hardly qualified to comment on the mechanisms of climate change, especially in view of the fact that many of the signatories have links to the fossil fuel industry.
Read more about the evidence for anthropogenic climate change here and here .
This article appears in the November 2019 version of Critical Links.