Category: global warming

Study says global warming ups odds of Southwest megadrought

Heat-trapping greenhouse gases may dessicate Colorado River Basin

The paradox of water in the desert, illustrated by a NASA satellite image of the Colorado River.
Megadroughts ahead? Satellite photo of the Colorado River Basin via NASA.

Staff Report

It’s very likely the southwestern U.S. will be hit by droughts unlike any seen since the region was settled by Europeans. Global warming has driven the odds of a 10-year drought to at least 50 percent, and the chances of a 35-year megadrought range from 20 to 50 percent during the next century, according to a new study led by researchers with Cornell, the University of Arizona and the U.S. Geological Survey.

Global warming is “weighting the dice” for megadroughts, said lead study author Toby Ault, explaining that the buildup of greenhouse gases is shifting the climate dramatically. The study is set to be published in an upcoming issue of the  American Meteorological Society’s Journal of Climate. Continue reading “Study says global warming ups odds of Southwest megadrought”

Melting Arctic may not be to blame for slowdown in critical Atlantic Ocean current

A pool of icy water twice the size of Lake Victoria could disrupt the Gulf Stream when it pours out of the Arctic Ocean into the Atlantic.
A new study tries to determine why a key Atlantic Ocean current is slowing down.

New study eyes link to Southern Hemisphere

Staff Report

A slowdown of a key heat-carrying Atlantic current may not be due to melting Arctic ice, but to changes in the Southern Hemisphere, according to University of Washington scientists studying how climate change may affect global wind and ocean flows.

Their new study, published in the journal Geophysical Research Letters, analyzed data from satellites and ocean sensors off Miami that have tracked the Atlantic overturning circulation for more than a decade. Together they show a definite slowdown since 2004, confirming a trend suspected before then from spottier data.

Several recent studies have warned that a large influx of cold, fresh water from the melting Arctic might be impeding the current, which moves warmer water north along the ocean’s surface and sends cold water southward at depths. But the latest research found that changes in the Southern Hemisphere may be a bigger factor. Continue reading “Melting Arctic may not be to blame for slowdown in critical Atlantic Ocean current”

Paris climate deal hits threshold to take effect

Can the world live up to the Paris climate agreement? @bberwyn photo.

Now the real work begins

By Bob Berwyn

The Paris climate agreement has reached the milestones needed to take effect, as 70 countries, representing almost 57 percent of global emissions, have formally signed on to the deal. According to the United Nations, Canada, the European and Nepal deposited their instruments of ratification with the global body Wednesday, Oct. 6. The agreement, aimed at limiting global warming to 1.5 degrees Celsius above the pre-industrial level, will become effective Nov. 4.

In a prepared statement, UN Secretary General Ban Ki-moon said, “Global momentum for the Paris Agreement to enter into force in 2016 has been remarkable. What once seemed unthinkable is now unstoppable. ”

Under the agreement, more than 190 countries agreed late last year to try and decarbonize the world’s energy systems by the middle of the century to end the buildup of heat-trapping pollution that has already raised the world’s average temperature by about 1 degree Celsius since 1850. In the past few months, the global temperature has spiked near the 1.5 degree threshold. Climate scientists agree that capping the rise at 2 degrees is critical to avoiding catastrophic climate change impacts like deadly droughts and heatwaves, floods and other extreme weather events.

The treaty also requires richer countries to set up a mitigation fund to help developing countries adapt to impacts. All countries party to the deal must submit individual plans and update them on a regular basis.

Commenting on the news from the Rose Garden, President Barack Obama said that, if the world follows through on the deal’s terms, “history may well judge it as a turning point for our planet.” More from the White House here.

Making it real will require a massive transformation of the world’s economy, and despite the good intentions, there are not many strong signs that will actually happen soon enough. Some recent studies have also warned that the planet is just 15 years away from hitting the 1.5 degree threshold, and that without immediate and massive greenhouse gas cuts, the 2-degree Celsius mark will be passed as early as 2050.

Understanding the urgency, the world community may try to ramp up climate action as soon as the COP22 climate conference in Marrakesh in November.

Antarctic sea ice peaks near record-low extent

Australian scientists document early start to melt season

Yes, there is still lots of ice in Antarctica, but it's melting faster than ever. bberwyn photo.
Yes, there is still lots of ice in Antarctica, but it’s melting faster than ever. bberwyn photo.
Antarctic sea ice extent was near a record low in late September and early October. Via NSIDC.

Staff Report

Australian scientists say Antarctic sea ice started its annual spring retreat early this year and has set new daily record lows for extent during late September — during the Austral spring, when Antarctic sea ice is at a maximum.

In a press release, the Antarctic Climate & Ecosystems Cooperative Research Centre said the sea ice extent started its annual retreat early, just two years after  winter sea ice extent around Antarctica reached a new record high in September 2014, when it exceeded 20 million square kilometres for the first time since satellite measurements began in 1979.

This year, Antarctic sea ice began its annual spring retreat about four weeks earlier than average, after peaking at 18.5 million square kilometres on 28 August 2016, which was close to the lowest winter maximum on record.

Continue reading “Antarctic sea ice peaks near record-low extent”

Climate connections

Fish die-offs spread, winter retreats and ocean currents are changing

The meltdown of glaciers and ice shelves around both poles is starting to affect the circulation of the oceans. @bbberwyn photo.

By Bob Berwyn

My recent reporting for InsideClimate News includes coverage of the massive Yellowstone fish kill, something that anglers and fisheries managers in Colorado also should probably be prepared for as rivers warm to a level that is conducive to the spread of parasites. Read the details here: Fish Deaths in Montana’s Yellowstone River Tied to Warming Waters.

I also explored how Austria is preparing for climate change. The mountainous country has seen its average temperature increase at nearly twice the global average in the past century, with huge implications for water supplies, agriculture, urban heatwaves and tourism. But rather than argue about the causes, Austrians are actively trying to figure out how to make their society and ecosystems more resilient to the changes ahead. Read here: Austria Braces for Winter’s Retreat.

There’s other research showing a significant shift in most key ocean currents that run along the edges of continents. Those currents are key drivers of weather systems and the changes documented by scientists suggest that the currents are strengthening and transporting more heat, which is affecting weather in densely populated areas. China and Japan, in particular, can expect more devastating storms and typhoons in the future: In Warming Oceans, Stronger Currents Releasing Heat in Bigger Storms.

It seems pretty clear that we have to try and prevent runaway climate change and the way to do that is to stop spewing heat-trapping pollution into the sky. We need to bite the bullet and figure out how to decarbonize our energy systems and economy in the most rational way, which means making plans and decisions now, not in 20 years. Every additional dollar used to subsidize fossil fuels, or to build fossil fuel infrastructure, is another nail in our own coffin. Offshore wind power is still grossly under-utilized in the U.S. but that is starting to change.

Offshore wind makes so much sense because the power sources can developed near the large coastal cities that are the largest consumers of power from the grid. Here’s how Hawaii is approaching the issue: Hawaii Eyes Offshore Wind to Reach its Clean Energy Goal.

European environmental groups push EU to act on climate

Civic groups brainstorm green policies at Vienna meeting

What’s left of the glaciers around the Grossglockner, Austria’s highest peak, makes it clear why Europe must act on climate. @bberwyn photo.

By Bob Berwyn

European environmental leaders this week called on the EU adopt an innovative mindset for dealing with climate and energy issues. Europe stands to gain from adopting progressive policies that create economic opportunities for businesses and improve life for citizens.

“Innovation, research and development will be at the center of decarbonising,” said Angela Köppl, speaking at the Sept. 26 annual meeting of the European Environmental Bureau in Vienna.The EEB is an umbrella for about 150 NGOs, think tanks and other civic groups representing more than 15 million citizens. Continue reading “European environmental groups push EU to act on climate”

How long can the oceans soak up CO2?

What’s the tipping point?

Researchers examine ocean acidification rates

Staff Report

For now, the world’s oceans are sucking up so much carbon dioxide that it’s helping to slow the rate of global warming. But that’s expected to change in the future, researchers warned after taking a detailed look at the rate of ocean acidification in the northeast Pacific Ocean. Continue reading “How long can the oceans soak up CO2?”