- The Climate Science Special Report spans more than 600 pages and is part of a larger report known as the Fourth National Climate Assessment
- Findings of the report at odds with the position of US President Donald Trump
- Trump has labeled global warming a Chinese hoax
- Named fossil fuel ally Scott Pruitt to head the Environmental Protection Agency
The US government has released a major scientific report that says climate change is real, ‘extremely likely’ to be caused by human activity, and affecting the daily lives of Americans.
The findings of the federally mandated report are starkly at odds with the position of US President Donald Trump, who has labeled global warming a Chinese hoax and named fossil fuel ally Scott Pruitt to head the Environmental Protection Agency.
The Climate Science Special Report spans more than 600 pages and is part of a larger report known as the Fourth National Climate Assessment.
The federally mandated report is starkly at odds with the position of US President Donald Trump, who has labeled global warming a Chinese hoax and named fossil fuel ally Scott Pruitt to head EPA
The government is required to produce the National Assessment every four years.
It has been split into two documents, one that lays out the fundamental science of climate change and the other that shows how the United States is being impacted on a regional basis.
Combined, the two documents total over 2,000 pages.
The first document, called the Climate Science Special Report, is now a finalized report, having been peer reviewed by the National Academy of Sciences and vetted by experts across government agencies.
Based on ‘a large body of scientific, peer-reviewed research,’ global annually averaged surface air temperature has increased by about 1.8 Fahrenheit (1.0 Celsius) over the last 115 years (1901-2016), it says.
‘This period is now the warmest in the history of modern civilization,’ said the report, available here.
It was compiled by the National Oceanographic and Atmospheric Administration, with contributions from NASA, the Department of Energy and other federal agencies.
Since the last report of its kind was issued in 2014, ‘stronger evidence has emerged for continuing, rapid, human-caused warming of the global atmosphere and ocean,’ it said.
‘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 has been the dominant cause of the observed warming since the mid-20th century,’ the report added, noting there ‘is no convincing alternative explanation.’
(left) Global annual average temperature has increased by more than 1.2°F (0.7°C) for the period 1986–2016 relative to 1901–1960. Red bars show temperatures that were above the 1901–1960 average, and blue bars indicate temperatures below the average. (right) Surface temperature change (in °F) for the period 1986–2016 relative to 1901–1960. Gray indicates missing data.
After examining long-term climate records and data going back thousands of years, the report said that in the modern era, ‘average temperatures in recent decades over much of the world have been much higher, and have risen faster during this time period than at any time in the past 1,700 years or more.’
The findings came as no surprise to climate scientists.
‘This isn’t new,’ said Peter Gleick, president-emeritus of the Pacific Institute and a member of the US National Academies of Science.
The US government’s Fourth National Climate Assessment says that that human activities, ‘especially emissions of greenhouse gases’ like carbon dioxide fumes from vehicles, are primarily responsible for climate change
Global annual average radiative forcing change from 1750 to 2011 due to human activities, changes in total solar irradiance, and volcanic emissions. Black bars indicate the uncertainty in each.
‘This is news only because Trump couldn’t censor it,’ he said on Twitter.
The Trump administration has repeatedly denied or downplayed the role of fossil fuels in global warming.
EPA chief Pruitt shocked scientists earlier this year when he argued in a media interview that carbon dioxide was not a primary contributor to global warming.
The NOAA said the report ‘serves as the foundation for efforts to assess climate-related risks and inform decision-making about responses.’
The last report of its kind came out in May 2014.
Democratic Senator Al Franken of Minnesota and eight of his colleagues this week sent a letter to Trump asking ‘what safeguards are in place to ensure that the National Climate Assessment and the Climate Science Special Report give fair and accurate summations of the latest climate science without political interference.’
The senators also asked how the Trump Administration plans to address the report’s findings.
The two panels above show annual historical and a range of plausible future carbon emissions in units of gigatons of carbon (GtC) per year (left) and the historical observed and future temperature change that would result for a range of future scenarios relative to the 1901?1960 average, based on the central estimate (lines) and a range (shaded areas, two standard deviations) as simulated by the full suite of CMIP5 global climate models (right).