Fact-checking a CNN story
CNN announces details for climate crisis town hall
Washington (CNN) CNN on Tuesday announced the candidate lineup for its unprecedented prime-time event focused on the climate crisis.
“pre-industrial” means the harsh “Little Ice Age” (LIA). Scientists call the current warm period a “climate optimum,” because it is unambiguously improved, compared to the pre-industrial LIA.
Nobody knows just how much colder the Earth’s average temperature was during the LIA, but most estimates are about 1°C, so we’ve already seen about 2/3 of that “1.5 degrees Celsius” of warming — and it has been beneficial, rather than harmful. By 2030 we’re likely to see only another 0.1 to 0.2 °C, not 0.5 °C, but even another 0.5°C would be hardly noticeable.
Climate activists rarely mention how challenging it is to measure the tiny temperature differences which characterize “global warming.” This graph, contrasting different global temperature indices, illustrates the problem. Even for the last sixty years, estimates of “measured” warming vary by a factor of two! Earlier time periods are known with even less certainty, and projections for the future are most uncertain of all:
If you understand graphs, then it should be obvious that rising CO2 levels have not affected sea-level:
That’s one of the highest-quality sea-level measurement records in the world, from a near-ideal central Pacific location, on an old, tectonically-stable island, with little or no vertical land motion, and a very typical sea-level trend.
Here’s what that very slight rise looks like on the ground. These are two photos of the Moana Surfrider Hotel, on Waikiki Beach, in Honolulu, taken nearly a century apart. Does it look like sea-level rise is a problem?
The benefits of extra CO2
for crops have been known to science for over a century. It is so dramatically beneficial that commercial greenhouses use CO2 generators to elevate daytime CO2 levels to 3-4 times outdoor levels. The benefits are so great that way back in 1920 Scientific American called it “the precious air fertilizer.” From this photo, which accompanied the article, you can certainly see why:
The widely repeated claim that July, 2019 was the hottest month ever is based on faulty data. It was warmer than average, but the best data indicates that it was only approximately the 4th warmest of the last 41 years.
For as long as we have measurement data, Greenland has been slowly losing ice. In an average year it loses about 200 billion tonnes (Gt) of ice, which sounds like a lot, but it is actually negligible. It is equivalent to less than three-hundredths of an inch of sea-level. I.e., at the current rate, meltwater from Greenland will contribute to less than three inches of sea-level rise by year 2100.
At the current rate, to melt entirely it would take the Greenland Ice sheet 100 to 150… …you thought I was going to say “years,” didn’t you?
Nope, not years.
Not decades, either.
Centuries. 100-150 centuries.
The rate of ice loss from the Greenland Ice Sheet fluctuates, but there’s no evidence of a sustained acceleration due to manmade climate change. In fact, in both of the last two glaciological years, Greenland had no net loss of ice at all (which is unusual).
will be available.