New federal climate report: it just keeps getting worse

A new federal climate report rejects the positions of much of the U.S. government’s executive branch under President Donald Trump, and slaps down climate denial.

The New York Times said the U.S. Global Climate Change Program’s Climate Science Special Report was approved for release by the White House, but the Times quoted scientists who wonder how the Administration squares its climate positions with the science.

“This report has some very powerful, hard-hitting statements that are totally at odds with senior administration folks and at odds with their policies. It begs the question, where are members of the administration getting their information from? They’re obviously not getting it from their own scientists,” said Philip B. Duffy, president of the Woods Hole Research Center, quoted in the Times. 

The climate report is unequivocal. Not only is human activity “extremely likely” to be causing climate change, but there is no longer any rational alternative explanation for what we’re seeing in climate, the report says.

For the Hawaiian Islands, the report presents a bleak outlook. For example, while Hawaii coastal geology experts have presented alarming predictions of the impacts of a 1-4-foot rise in sea levels, the new Climate Science Special Report says 8 feet is not impossible by the end of the century.

That would entirely reshape Island coastlines, drowning some of our most expensive properties, destroying harbors and flooding airports, and driving saltwater intrusion into our groundwater reservoirs.

The report’s conclusions suggest possible consequences far worse than the scenarios being considered by the Hawai`i Climate Change Mitigation and Adaptation Commission. 

That commission is charged with overseeing the state’s response to climate change, and its first task is the development by the end of 2017 of a sea level rise and adaptation report.

University of Hawai`i coastal geologist Chip Fletcher said that just a few years ago, 3 to 4 feet of sea level rise was a worst case scenario, but climate change has advanced so fast that it’s now a mid-range view.

“We need to model two meters (more than 6 feet) of rise and see what that looks like,” Fletcher said.

Perhaps the most frightening suggestion in the new federal climate report is that things are changing so fast that there may be impacts we can’t predict—ones we don’t see coming.

“There is significant potential for humanity’s effect on the planet to result in unanticipated surprises and a broad consensus that the further and faster the Earth system is pushed towards warming, the greater the risk of such surprises,” the report says.

“That’s been one of our concerns: feedbacks that we can’t predict,” Fletcher said.

Here is some of the opening language of the Climate Science Special Report, prepared by more than a dozen agencies of NOAA, NASA and the Department of Energy, operating together as the U.S. Global Climate Change Program.

“This assessment concludes, based on extensive evidence, that 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.”

For Hawai`i, the report’s key statistics are sobering, and familiar. We will focus on the actual language of the report to minimize suggestions that they are being overstated.

SEA LEVELS COULD GO UP A LOT, AND MAYBE MORE THAN A LOT

It says sea levels have risen 7 to 8 inches in the past century, and the rate of rising is increasing. It has come up 3 inches since 1993.

“The incidence of daily tidal flooding is accelerating in more than 25 Atlantic and Gulf Coast cities,” the report says.

And for the future?

“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.”

HEAVY RAIN EVENTS MORE COMMON

“Changes in the characteristics of extreme events are particularly important for human safety, infrastructure, agriculture, water quality and quantity, and natural ecosystems. Heavy rainfall is increasing in intensity and frequency across the United States and globally and is expected to continue to increase.”

Because of incomplete data, the report did not make specific predictions for heavy rain events in the Hawaiian Islands.

NO AVOIDING INCREASING HEAT

“Over the next few decades (2021–2050), annual average temperatures are expected to rise by about 2.5°F for the United States, relative to the recent past (average from 1976–2005), under all plausible future climate scenarios…

‘Without major reductions in emissions, the increase in annual average global temperature relative to preindustrial times could reach 9°F (5°C) or more by 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.”

MARINE LIFE THREATENED BY WARMING, INCREASING ACIDIFICATION, DECLINING OXYGEN

“The rate of acidification is unparalleled in at least the past 66 million years. Under the higher scenario the global average surface ocean acidity is projected to increase by 100% to 150%.”

“Increasing sea surface temperatures, rising sea levels, and changing patterns of precipitation, winds, nutrients, and ocean circulation are contributing to overall declining oxygen concentrations at intermediate depths in various ocean locations and in many coastal areas.”

CARBON DIOXIDE GROWTH IN ATMOSPHERE SLOWING, BUT NOT ENOUGH

“In 2014 and 2015, emission growth rates slowed as economic growth became less carbon-intensive. Even if this slowing trend continues, however, it is not yet at a rate that would limit global average temperature change to well below 3.6°F (2°C) above preindustrial levels.”

The University of Hawai`i’s Fletcher said he was surprised that the report was publicly published in spite of the Trump administration’s antipathy to climate science.

“I think it shows that they haven’t yet swept the staff wholesale out of these agencies,” Fletcher said.

© Jan TenBruggencate 2017

USGCRP, 2017: Climate Science Special Report: Fourth National Climate Assessment, Volume I [Wuebbles, D.J., D.W. Fahey, K.A. Hibbard, D.J. Dokken, B.C. Stewart, and T.K. Maycock (eds.)]. U.S. Global Change Research Program, Washington, DC, USA, 470 pp.