The NCA4, as it's known, is the nation's most authoritative assessment of climate science. The global, long-term warming trend is "unambiguous", the report says, and there is "no convincing alternative explanation" that anything other than humans - the cars we drive, the power plants we operate, the forests we destroy - are to blame.
The United Nations convenes its annual climate change conference next week in Germany, and the Trump delegation is expected to face criticism over the president's decision to walk away from the Paris accord on climate and top USA officials' stated doubts about the causes and impacts of a warming planet.
"I believe that measuring with precision human activity on the climate is something very challenging to do", EPA Administrator Scott Pruitt said in an interview earlier this year. Sea ice that foiled famous explorers and blocked the passage to all but the hardiest ships has slowly been melting away in one of the most visible effects of man-made global warming.
Global annually averaged surface air temperature has increased by about 1.8 degrees Fahrenheit from 1901 to 2016.
If you're wondering what could have changed since the last report in 2014, the new Assessment highlights a list of areas in which our understanding has improved. "As the Climate Science Special Report states, the magnitude of future climate change depends significantly on 'remaining uncertainty in the sensitivity of Earth's climate to [greenhouse gas] emissions'". The report also notes that warmer temperatures have contributed to the rise in forest fires in the West and that the incidence of those fires is expected to keep rising. Global average sea level has risen 7-8 inches since 1900 -half of that rise has happened in the last 25 years, and daily tidal flooding has gotten worse in more than 25 Atlantic and Gulf Coast states.
Starcraft II Goes Free-To-Play
If you have already bought any of those, then you'll soon be receiving an exclusive Ghost skin and three new portrait options. All StarCraft II expansions will be available individually for $14.99 and will be available as a bundle for $39.99.
The report also points out that heavy rainfall is increasing in intensity and frequency across the US, especially in the Northeast, and that is expected to keep increasing. And it provides this sobering reminder: "The present-day emissions rate of almost 10 [billion tons of carbon] per year suggests that there is no climate analog for this century any time in at least the last 50 million years".
While I agree that I think China has definitely taken advantage and abused many climate change regulations, I was always confused by what he meant by the tweet, especially since most climate change statistics are pretty hard to disbelieve. Licker also noted that the authors of the NCA4 and the CSSR reviewed 1,500 scientific studies and reports before drawing conclusions. Alley said that there seems to be no indication that the report has been soft-pedaled or that the science behind it has been downplayed to be uncertain.
Alley notes that "there's a little rumbling" among climate scientists who are concerned that the Trump administration will ignore this effort.
The report has been submitted to the Office of Science and Technology Policy at the White House.
To his credit and despite the rhetoric coming from the administration for the past year, Trump did not have the report edited like some of his predecessors did (George W. Bush reportedly had the assessment, which comes out every four years, heavily tweaked to favor his administration's policies).