Quantcast
Popular
Pacific Ocean sunset in San Diego. Michael Matti / Flickr

Global Warming ‘Hiatus’ Is Over

By Tim Radford

It is official. The world is warming according to expectations. The so-called and much debated "pause" in global warming is over. And the culprit that tried to cool the planet in spite of ever-rising levels of carbon dioxide in the atmosphere?

Blame it on the Pacific Ocean. It went into a not-so-hot phase, part of a long-term natural cycle, which has now come to an end. This explains the apparent slowdown in the rate of global warming. The verdict comes from the UK Met Office, which is host to the oldest continuous record of temperatures in the world, and which pioneered weather science.


"After a period during the early 2000s when the rise in global mean temperature slowed, the values in 2015 and 2016 broke records and passed 1°C above pre-industrial levels," said professor Stephen Belcher, chief scientist at the Met Office. "Data from the Met Office shows that the long-term rate of global warming has now returned to the level seen in the second half of the 20th century."

The so-called hiatus in global warming between 1999 and 2014 was a phenomenon much hailed by climate deniers as evidence that global warming did not exist, or had stopped. But it also provided the climate scientists, oceanographers, glaciologists and weather forecaster of the planet with a puzzle: why did the atmospheric temperature not conform to expectations? What followed would provide academics with a case study of how science is done: researchers around the world looked at the problem in a score of ways, and delivered what may be a dozen tentative answers.

Global warming records

First, the record: for the second half of the 20th century, the world warmed, steadily and consistently, in line with predictions based on the greenhouse effect. That is, carbon dioxide pumped into the atmosphere through profligate fossil fuel use since the Industrial Revolution, was trapping infrared radiation and warming the planet.

But for the first decade and a half of this century, the rate of warming slowed. Some researchers reasoned that the effect would be temporary while others considered the evidence again and wondered if there could be said to have been a slowdown at all: the evidence was either illusory or only looked like a slowdown considered in the short term. Other researchers argued that even if average rates of rise seemed to have dropped, the number of extremes of heat had increased or that an increase in the number of volcanic eruptions might be masking solar radiation and lowering the temperatures.

Role of oceans

Yet further groups suggested that the oceans had played an unexpected role or that such an apparent slowdown made no difference: warming would happen as usual.

For three years, global temperature records were broken, each year hotter than the last and in 2016, the global average temperature stood at 1°C above the long-term industrial average. Part of the explanation is that global temperatures were heightened by a natural phenomenon in the Pacific Ocean called El Niño. But for a decade or so earlier in the century, another Pacific feature was slowly unfolding: the Pacific Decadal Oscillation, which blows warm and cool, in a cyclic pattern. And this time, said Met Office scientists, it damped down the rate of global warming.

This year is unlikely to break all records. But, the Met Office chiefs said, the rate of warming has increased: the world will go on getting hotter.

"The end of the recent slowdown in global warming is due to a flip in Pacific sea-surface temperatures," said Adam Scaife, who heads monthly-to-decadal prediction for the Met Office. "This was due to a change in the Pacific Decadal Oscillation which entered its positive phase, warming the tropics, the west coast of North America and the globe overall."

Reposted with permission from our media associate Climate News Network.

Show Comments ()

EcoWatch Daily Newsletter

Sponsored
Climate
Women fetching water in India. Pixabay

India Suffers 'Worst Water Crisis in Its History'

India is facing its "worst-ever" water crisis, according to a report from a government think tank issued last week.

Around 200,000 Indians die each year due to lack of water access, the report finds, and demand will be twice as much as supply by 2030.

Keep reading... Show less
Food
daryl_mitchell / Flickr / CC BY-SA 2.0

Urban Gardening 101: How to Deal With Contaminated Soil

By Brian Barth

Urban soils are particularly prone to contamination. Fifty years ago, your yard could have belonged to a farmer, who, perhaps not knowing any better, disposed of old bottles of anti-freeze or contaminated diesel in a hole out behind the tractor garage. Or perhaps the remains of a fallen down outbuilding, long ago coated in lead-based paint, was buried on your property buy a lazy contractor when your subdivision was built.

Keep reading... Show less
Climate
High-tide flooding in Miami, FL, a state that could lose more than 10 percent of its residential properties to chronic flooding by 2100. B137 / CC BY-SA 4.0

Sea Level Rise Could Put 2.4 MIllion U.S. Coastal Homes at Risk

More than 300,000 U.S. coastal homes could be uninhabitable due to sea level rise by 2045 if no meaningful action is taken to combat climate change, a Union of Concerned Scientists (UCS) study published Monday found.

The study, Underwater: Rising Seas, Chronic Floods and the Implications for U.S. Coastal Real Estate, set out to calculate how many coastal properties in the lower 48 states would suffer from "chronic inundation," non-storm flooding that occurs 26 times a year or more, under different climate change scenarios.

Keep reading... Show less
Climate

NASA Climate Scientist Warned Us About Warming 30 Years Ago

Climate science marks a troubling anniversary this week: in June of 1988, NASA scientist James Hansen told Congress that global warming had already begun to affect the world and would only get worse.

Keep reading... Show less
Sponsored
Climate
Pixabay

4 Ways You Can Make a Difference on Climate

By Jaime Nack

"Where do I start?"

Whatever the forum, whatever the audience, it's always the first question I hear when I talk to people about sustainability and personal impact.

Keep reading... Show less
Renewable Energy
Minnesota Senate Building solar array ribbon-cutting ceremony on May 10. MN Administration / CC BY 2.0

U.S. Sees Steady Solar Growth Despite Trump, But China Slashes Subsidies

By Andy Rowell

Donald Trump can't stop the sun from shining. Despite the climate denier's pro-fossil fuel agenda, and despite his tariffs on imported solar panels, the U.S. still installed more solar than any other source of energy in the first quarter of the year.

The amount of solar power installed in the U.S. climbed 13 percent in the first quarter, according to the trade body, the Solar Energy Industries Association (SEIA).

Keep reading... Show less
Sponsored
Politics
frankieleon / CC BY 2.0

How a Minor Change to EPA Rules Could Slash Environmental Protection

By Joseph Aldy

Since the Reagan administration, federal agencies have been required to produce cost-benefit analyses of their major regulations. These assessments are designed to ensure that regulators are pursuing actions that make society better off.

In my experience working on the White House economic team in the Clinton and Obama administrations, I found cost-benefit analysis provides a solid foundation for understanding the impacts of regulatory proposals. It also generates thoughtful discussion of ways to design rules to maximize net benefits to the public.

Keep reading... Show less
Popular
E. Kahl / National Park Service

America’s Most Obscure Desert Is in Alaska

By Michael Engelhard

Time slipping, a tabula rasa. Footprints erased, slopes advanced, ripples unsculpted. A whole world recast by whims of weather. Besides snowfields and foreshores, few landscapes appear so clean-cut and subtle. Here, emptiness is the main attraction.

Keep reading... Show less
Sponsored

mail-copy

The best of EcoWatch, right in your inbox. Sign up for our email newsletter!