Archive for the ‘climate change’ Category

Thousands of years ago, a warm Arctic made mid-latitudes drier

March 28th, 2019
The Arctic is the fastest-warming region of the planet.

Enlarge / The Arctic is the fastest-warming region of the planet. (credit: NASA)

The thing about a global climate change is that it isn’t as simple as shifting the temperatures everywhere by a set number of degrees. The temperature change isn’t uniform around the globe, and these regional differences can drive considerable knock-on effects on weather patterns.

The Arctic, for example, will warm more than the equatorial region. For our current global warming venture, there will be consequences of this fact beyond the Arctic itself. One juicy hypothesis is that the greater Arctic warming affects the behavior of the polar jet stream, driving significant changes on extreme weather patterns in the mid-latitudes. This idea is the subject of ongoing research, as well as genuine scientific debate and uncertainty.

Lessons from the past

One way to study patterns like this is to look to past climate changes. That’s what a team led by Northern Arizona University’s Cody Routson did, compiling paleoclimate records of rainfall in the Northern Hemisphere over the last 10,000 years.

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Posted in climate change, paleoclimate, science | Comments (0)

You can help “rescue” weather data from the 1860s

March 22nd, 2019
The wreck of the Royal Charter in 1859 led to systematic weather observations in the UK—but researchers need help reading them all.

Enlarge / The wreck of the Royal Charter in 1859 led to systematic weather observations in the UK—but researchers need help reading them all. (credit: Wikimedia)

“Weather Rescue” sounds like it could be a Baywatch-style TV show about the adventures of an emergency response team. But the Weather Rescue project led by University of Reading researcher Ed Hawkins is actually focused on data that need rescuing.

The UK Met Office has an incredible trove of historical weather data in its archives that is trapped on paper. While it’s safe there, scientists need it in digital form in order to do anything interesting with it. The collection goes all the way back to 1860 and includes the first weather forecasts coordinated by Vice-Admiral Robert FitzRoy—the same Robert FitzRoy who captained the HMS Beagle on Charles Darwin’s historic trip.

After a storm sunk 200 ships off the coast of Wales (including the Royal Charter and its crew of 450), FitzRoy set about creating a network of UK weather stations that could telegraph daily observations to him in London. In February 1861, he put out the first forecast storm warning. After some of the fishermen who ignored this new-fangled sorcery sank in the storm, the forecasts encountered an increasingly attentive audience.

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Posted in citizen science, climate change, science | Comments (0)

Shading the planet doesn’t have to come with rainfall side-effects

March 13th, 2019
Shading the planet doesn’t have to come with rainfall side-effects

Enlarge (credit: Caetano Candal Sato)

It sounds like a drastic course of action: inject stuff high into Earth’s atmosphere to reflect a little sunlight and help counteract global warming. Then again, injecting a bunch of greenhouse gas into the atmosphere and warming the planet was pretty drastic, too.

The key to thinking sensibly about this “solar geoengineering” is to avoid the extremes and consider the most plausible use scenarios. That means we can ignore things like using solar geoengineering to cancel out all warming while still emitting as much CO2 as we please—it simply isn't plausible.

There are a number of reasons to take it off the table. There’s the fact that the cooling influence of atmospheric injections is only temporary—quitting quickly reveals the full force of the warming you’re offsetting. There’s also the fact that this scheme only counteracts warming—the acidification of the oceans would continue apace. And for another example, the mismatch in physics between solar-geoengineering-driven cooling and greenhouse warming means that precipitation can decline even if temperature stays the same.

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Posted in climate change, Geoengineering, science | Comments (0)

Ocean heat waves remake Pacific and Caribbean habitats

March 5th, 2019
Image of three corals

Enlarge / Although these corals are colored, they've been bleached, in that they have lost their photosynthetic symbiotes. (credit: ARC Centre of Excellence for Coral Reef Studies / Gergely Torda)

Climate change tends to deal in averages. We measure its progress using the global mean temperature, and we use climate models to project what that value will be in the future. But those average changes don't always capture what future climate change will be like. While you can raise an average by increasing every day's temperature by a tiny amount, but it's also possible to raise an average by throwing in an occasional extreme event. to do so by throwing in an occasional extreme event. Heat waves and extreme storms have indicated that nature seems to be going for the latter option.

A new paper shows that this kind of climate change isn't just affecting the sorts of weather we typically experience; it's happening in the oceans as well. The study shows that, over the course of less than a century, the frequency of oceanic heat waves went up by over 50 percent. The study looked into the effects these events are having on ecosystems, and it showed that we're pushing species toward the poles without affecting all of them equally.

Heating the ocean's waves

When the subject is the atmosphere, the common practice is to track the frequency and extent of heat waves and even to determine if they have been influenced by climate change. In contrast, there was no widely accepted definition of when warming waters constituted a heat wave until 2016. That's in part because of the differences in the driving process and scale. Localized ocean heat waves can be driven by a corresponding heat wave in the atmosphere, while El Niño events are driven by large-scale current patterns that influence most of the Pacific.

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Posted in Biology, climate change, Earth sciences, Ecology, heat waves, oceanography, science | Comments (0)

Migrating blue whales rely on memory to find their feeding grounds

February 27th, 2019

Breakfast spots, coffee shops, and watering holes pepper the daily commutes of modern urban humans, but we try to remember the ones where we get the best food or drinks. If we do longer journeys routinely, we also keep track of the best grazing grounds—a diner, a gas station with the best snacks, and so on.

Blue whales, according to research published in PNAS this week, seem to make similar mental notes. On their annual migration, their path takes in the spots that have proven to be the most reliable feeding grounds over the years. In doing this, the whales may bypass hotspots that pop up and fade from one year to the next, suggesting that they rely heavily on memory to find a solid meal. But in a world where “normal” is shifting rapidly, the endangered whales may no longer be able to rely on the abundance of those old, faithful feeding grounds.

Why do whales go where they go?

Blue whales are the largest animal that we know to have lived, and that means they need colossal amounts of food. Despite this, they’re picky eaters, feeding almost exclusively on small crustaceans called krill, which they eat by lunging through a large swarm with an open mouth, trapping the animals in their mouths while the sea water filters back out. And they manage to find sources of food while migrating from a summer near the poles to a winter spent closer to the equator.

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Posted in Behavioral science, Biology, climate change, science | Comments (0)

Trump climate advisory panel structured to avoid public records

February 25th, 2019
A global snapshot of the Vegetation Sensitivity Index (VSI) from 2016. The VSI measures environmental sensitivity to a changing climate, using satellite data gathered between 2000-2013 at 5km resolution. Areas in green are covered in vegetation that is the least sensitive to changes. Areas in red show the highest sensitivity. Grey areas are barren land or ice covered. Water is blue.

Enlarge / A global snapshot of the Vegetation Sensitivity Index (VSI) from 2016. The VSI measures environmental sensitivity to a changing climate, using satellite data gathered between 2000-2013 at 5km resolution. Areas in green are covered in vegetation that is the least sensitive to changes. Areas in red show the highest sensitivity. Grey areas are barren land or ice covered. Water is blue. (credit: Sedon, et. al.)

As we reported last week, the White House hosted a cross-agency meeting regarding a plan to create an advisory committee specifically to attack the conclusions of its own climate scientists. Details of that meeting, and the plan that ensued, are now starting to leak out.

To begin with, The Washington Post indicates that the motivation for the effort was made clear during the meeting: Trump was upset by the release of the National Climate Assessment. The report is required by law, and its conclusions were solidly within the mainstream of the scientific community's conclusions on the climate, leaving very little room for attack. So, the White House has decided to select a group of government scientists that include members who are skeptical towards its conclusions.

The group will be structured so that it can do its work off the record. The Post notes that a formal Federal Advisory Committee would include having meetings in public and creating extensive public records of its deliberations. As a result, the new plan is to create an ad-hoc working group instead, which avoids the need for any public disclosure.

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Posted in anthropogenic climate change, climate change, Climate science, Policy, science, trump administration | Comments (0)

Trump’s mistrust of the intelligence community expands to the climate

February 22nd, 2019
William Happer, a retired Princeton physicist.

Enlarge / William Happer, a retired Princeton physicist. (credit: Gage Skidmore)

On Wednesday, the Washington Post reported that it had obtained a document suggesting that the Trump administration is considering combining two areas where it has consistently dismissed expert conclusions: climate change and intelligence analysis. While the intelligence community has consistently accepted that climate change creates security risks for the United States, the document suggests that Trump will circumvent its advice by setting up an advisory committee in an effort headed by a retired professor noted for not accepting the conclusions of the scientific community.

The document is a National Security Council discussion paper, and it suggests using an executive order to set up a Presidential Committee on Climate Security. The committee would provide advice to Trump on the current climate and its future changes and how those affect the national security of the US.

Adversarial

Normally, these functions are provided by the scientific community and the intelligence community, respectively. But these parties have been giving Trump evidence that he's not interested in accepting.

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Posted in climate change, national security, science, Science policy | Comments (0)

Montana legislator introduces bills to give his state its own science

February 21st, 2019
Image of a large, domed building.

Enlarge / The Montana State Capitol building, site of a rather unusual hearing. (credit: Montana.gov)

It's no secret that some of our federal legislators don't have a firm grip on scientific evidence; it only takes watching a session of the House Science Committee, where one member suggested the climate-driven rise of the oceans might instead be caused by rocks falling into the ocean.

What's often overlooked is that state legislators are even worse (though it's not clear how much this is a product of there simply being more of them). Each year, they oversee a variety of attempts to introduce pseudoscience into the public schools of a number of states.

But it recently came out that a legislator in Montana was attempting to have the state officially renounce the findings of the scientific community. And, if the federal government decides to believe the scientists and do something about emissions, he wants the Treasure State to somehow sit those efforts out.

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Posted in climate change, greenhouse gasses, montana, Policy, science, Science policy | Comments (0)

Want a better idea of your future climate? Try this map

February 14th, 2019
Want a better idea of your future climate? Try this map

Enlarge (credit: Alan Levine)

Absent a time machine, it’s hard to truly wrap your head around what the future climate will be like. Climate projection numbers carry a lot of information, but those numbers can seem abstract—what does 2.5º warmer actually feel like?

One way to understand that information is to hop in the car (even if it’s not a DeLorean). There are a huge variety of local climates around the world, and it’s possible to find a location today that ought to feel a lot like your hometown will in a few decades. A new study by Matt Fitzpatrick and Rob Dunn applies this “climate analog” approach to 540 cities in the US and Canada—which means about 250 million people can use a Web map to look for an analog to their future climate.

Present and future climates

There are multiple ways you could imagine defining such a comparison. In this case, the researchers broke the data down by season, calculating minimum/maximum temperatures and total precipitation averaged over 1960-1990. This is basically the seasonal weather you’re used to.

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Posted in climate change, North America, science | Comments (0)

Green New Deal bill aims to move US to 100% renewable energy, net-zero emissions

February 7th, 2019
Wind turbines on private working ranch land on August 1, 2017 near Kevin, Montana.

Enlarge / Wind turbines on private working ranch land on August 1, 2017 near Kevin, Montana. (credit: Getty Images / William Campbell-Corbis)

On Thursday morning, NPR posted a bill drafted by Representative Alexandria Ocasio-Cortez (D-NY) advocating for a Green New Deal—that is, a public works bill aimed at employing Americans and reducing greenhouse gas emissions in the face of climate change.

A similar version of the bill is expected to be introduced in the Senate by Senator Ed Markey (D-Mass.).

The House bill opens by citing two recent climate change reports: an October 2018 report from the Intergovernmental Panel on Climate Change and a heavily peer-reviewed report released in November 2018 by a group of US scientists from federal energy and environment departments. Both reports were unequivocal about the role that humans play in climate change and the dire consequences humans stand to face if climate change continues unchecked.

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Posted in climate change, Energy, Green New Deal, Policy | Comments (0)