Articles by Coby Beck

‘Some sites show cooling’–But you can’t draw global conclusions from individual sites

(Part of the How to Talk to a Global Warming Skeptic guide)

Objection: Some stations, in the U.S. for example, show cooling trends. If there were really global warming, it would be warming everywhere.

Answer: Global warming is the long-term increase in globally and seasonally averaged surface temperatures. It is not the case, nor is it expected, that all regions on the planet, let alone all weather stations, will show the same changes in temperature or rainfall patterns. Many stations have shown cooling, and some small regions have shown modest cooling as well. This does not invalidate global warming theory; it is merely the result of regional variation, and an example of how varied and complex the climate system is.

(source: NASA)

‘Climate sensitivity is not very high’–Thermal inertia of the oceans means the jury is still out

(Part of the How to Talk to a Global Warming Skeptic guide)

Objection: Taking into account the logarithmic effect of CO2 on temperature, the 35 percent increase we have already seen in CO2 concentrations represents about three-quarters of the total forcing to be expected from a CO2 doubling. Since we have warmed about 0.7 degrees Celsius so far, we should only expect about 0.3 degrees more for a doubling from pre-industrial levels, so about 1 degree total, not 3 degrees as the scientists predict. Clearly the climate model sensitivity to CO2 is much too high.

Answer: Even without addressing the numbers in this argument, there is a fundamental flaw in its reasoning.

‘Sea level in the Arctic is falling’–Sea level is a surprisingly complicated thing

(Part of the How to Talk to a Global Warming Skeptic guide)

Objection: According to the latest state-of-the-art satellite measurements from over the Arctic, sea levels are falling! Guess all that ice isn't melting after all.

Answer: Yes, a new study using Europe's Space Agency's ERS-2 satellite has determined that over the last 10 years, sea level in the Arctic Ocean has been falling at an average rate of about 2 mm/year. This is very new and very interesting news, though it is preliminary and not published in any peer-reviewed journals yet. But even if these results hold up to time and scrutiny, it is not evidence that globally sea levels are not rising, because they are.

‘Antarctic sea ice is increasing’–Yes, but …

(Part of the How to Talk to a Global Warming Skeptic guide)

Objection: Sure, sea ice is shrinking in the Arctic, but it is growing in the Antarctic. Sounds like natural fluctuations that balance out in the end.

Answer: Overall, it is true that sea ice in the Antarctic is increasing.

Around the peninsula, where there is a lot of warming [PDF], the ice is retreating. This is the area of the recent and dramatic Larsen B and Ross ice shelf breakups.

But the rest of the continent has not shown any clear warming or cooling and sea ice has increased over the last decade or so.

This is not actually a big surprise.