Climate change, the official stand of the U.S. government. Here are just a few of the highlights from the official report.
Although Punxsutawney, PA, USA is the home of the weather forecasting groundhog, Phil does not predict climate, only weather.
“Heavy rainfall is increasing in intensity and frequency across the United States and globally and is expected to continue to increase
Global annually averaged surface air temperature has increased by about 1.8°F (1.0°C) over the last 115 years (1901-2016). This period is now the warmest in the history of modern civilization. The last few years have also seen record-breaking, climate-related weather extremes, and the last three years have been the warmest years on record for the globe. These trends are expected to continue over climate timescales.
it is extremely likely that human activities, especially emissions of greenhouse gases, are the dominant cause of the observed warming since the mid-20th century. For the warming over the last century, there is no convincing alternative explanation supported by the extent of the observational evidence.
Thousands of studies conducted by researchers around the world have documented changes in surface, atmospheric, and oceanic temperatures; melting glaciers; diminishing snow cover; shrinking sea ice; rising sea levels; ocean acidification; and increasing atmospheric water vapor.
The incidence of large forest fires in the western United States and Alaska has increased since the early 1980s and is projected to further increase
Annual trends toward earlier spring melt and reduced snowpack are already affecting water resources in the western United States … chronic, long-duration hydrological drought is increasingly possible before the end of this century.
With significant reductions in emissions, the increase in annual average global temperature could be limited to 3.6°F (2°C) or less.
The global atmospheric carbon dioxide (CO2) concentration has now passed 400 parts per million (ppm), a level that last occurred about 3 million years ago, when both global average temperature and sea level were significantly higher than today.”
The above is all taken from the summary.
16 of the last 17 years set new record high-temperature marks.
Although President Trump is quickly trying to downplay his own government’s report online and by having it released during a major holiday so no one would see it, the truth is out there for anyone to see in the report.
I will only point out a single Trump falsehood about this major report but it is telling. The president has said everything is very exaggerated in the report, only giving the most extreme estimates.
Even reading only the Executive Summary you can see this: “Global average sea levels are expected to continue to rise by at least several inches in the next 15 years and by 1-4 feet by 2100. A rise of as much as 8 feet by 2100 cannot be ruled out. Sea level rise will be higher than the global average on the East and Gulf Coasts of the United States.”
Is that estimated range of 1 foot to possibly 8 feet ONLY the most extreme? Or, does it express every possibility from the lest possible expected change to the maximum estimated possible change?
Of course, as with EVERY climate change denier, President Trump either because he doesn’t understand the difference, or intentionally, confuses weather with climate.
You can choose to ignore the human contribution to climate change caused by CO2 levels in the atmosphere and that’s up to you, but even if humans aren’t responsible for climate change, that doesn’t prevent humans from trying to mitigate the terrible results which will inevitably follow.
If you wonder why this government has chosen to complete and publish this report it may be because it is required by a law passed in 1990, The Global Change Research Act.
The entire 4th Annual National Climate Assessment report Volume I is online.
https://science2017.globalchange.gov/
In addition to writing about science and technology for 45 years, I am a trained physicist and member of The Union of Concerned Scientists and The American Association for the Advancement of Science – JM.
