How Global Warming Could Make Nature Less Diverse

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John Schwartz

Hey there, everybody!

We kicked off this week with a story nearly as big as Alaska: how the Trump administration, Republicans in Congress and Alaskan officials are rapidly clearing a path for oil drilling in the Arctic National Wildlife Refuge in that state, even though most Americans oppose drilling there. Written by Henry Fountain and Steve Eder, with wonderful photos from Katie Orlinsky and Brian Adams, it’s a must-read.

But if you just don’t have the time (and if that’s the case, let’s talk about your priorities), Henry and Steve provided a set of quick takeaways from the project. You can also read their interview with a polar bear expert.

By the way, the Trump administration’s push to open up drilling — and to roll back the environmental regulations that can restrict it — is also in the news off the Atlantic coast of the United States, where the administration has approved seismic testing as a prelude to drilling. That could endanger marine life and coastal tourism, and you can expect any attempt to drill to be fiercely opposed by coastal states and environmental groups.

These moves are all part of the president’s “energy dominance” agenda, but that doctrine is itself threatened by climate change, as Lisa Friedman tells us.

Also this week, diplomats from around the world have gathered in Poland for the latest round of global climate talks; Brad Plumer will be there for NYT Climate. Negotiators are dealing with big questions: How thoroughly should countries report their progress on emissions? How detailed should their plans for making further cuts be? It’s all part of the hard work following the Paris climate deal.

There is much hard work ahead, a story from Kendra Pierre-Louis shows. After an enticing, three-year lull in greenhouse gas emissions, the last two years have shown a rise — and this year’s jump is expected to be bigger than last year’s. Researchers compared the increasing emissions to a “speeding freight train.”

And a new study is a reminder of what’s at stake: It suggests that climate change is posing immediate health hazards all around the world, according to a story from Somini Sengupta.

Back in the United States, we still have people arguing that climate change isn’t happening, and even that the scientists who have developed the overwhelming body of evidence are … in it for the money? Our colleague Linda Qiu debunked that baseless claim. And our media columnist, Jim Rutenberg, dinged the cable news networks for putting climate deniers on the air while shutting out actual experts. That’s the kind of thing that really bugs us.

And speaking of bugs ….

Kendra Pierre-Louis

If the natural world is a symphony, with different species forming the various sections of the orchestra, climate change is poised to make its music less rich.

That’s because biodiversity, the world’s immense variety of life, may shrink as the climate warms.

A study this year in the journal Science found that, if the planet warms by 3.2 degrees Celsius, or about 5.8 degrees Fahrenheit, then 49 percent of insects, 44 percent of plants and 26 percent of vertebrates will lose more than half of their geographic habitat. That is the level of warming predicted by 2100 if countries honor their current Paris Agreement pledges to reduce emissions.

The authors of the study used a database with information about the temperature and spatial needs of more than 100,000 plants, insects and other animals. They compared it to various climate scenarios and found that insects in particular would lose ground. Other recent research has found that insects are already in serious decline worldwide.

“Within North America a species, say, a bird, will have a preferred climate that it likes,” said Rachel Warren, a co-author of the study and professor of global change and environmental biology at the University of East Anglia. “It won’t be found north of that range because it’s too cold, and it won’t be found south of that range because it’s too hot.”

But as the climate warms, the species will have to move. If we let the planet warm by 3.2 degrees Celsius, most species will find fewer places that hit their thermal sweet spot, and many will die off.

The researchers also looked at what would happen if we limited warming to two degrees Celsius, the formal target under the Paris pact.

At that level of warming, 18 percent of insects, 16 percent of plants and 8 percent of vertebrates would lose more than half their range.

While the difference between two degrees and 3.2 degrees of warming may seem negligible, it’s not. During the last ice age, Dr. Warren said, the planet was only six degrees cooler than its preindustrial average.

“Three degrees is a half-ice-age,” Dr. Warren said. “In fact, the Earth would be almost unrecognizable if the planet warmed by three degrees.”

“Once that happens, really big impacts kick in.”

Karen Zraick

The Christmas tree is the centerpiece of the biggest holiday of the year for many families. Some cherish the scent of a real tree and the tradition of bringing it home, while others prefer the tidier and easier option of the plastic variety.

But which is better for the environment?

If you go with a real tree, don’t feel bad about cutting it down for the holiday. Christmas trees are crops grown on farms, like lettuce or corn. They are not cut down from wild forests on a large scale, said Bert Cregg, an expert in Christmas tree production and forestry at Michigan State University.

A five- or six-foot tree takes just under a decade to grow, and once it’s cut down, the farmer will generally plant at least one in its place. The trees provide many benefits to the environment as they grow, cleaning the air and providing watersheds and habitats for wildlife. They grow best on rolling hills that are often unsuitable for other crops and, of course, they are biodegradable.

Most of the artificial trees on the market are made of PVC and steel in China and shipped to the United States — and eventually sent to a landfill.

While that may not sound eco-friendly, the American Christmas Tree Association, which represents manufacturers, claims the environmental impact is lower than that of a real tree if you use the artificial tree for five or more years. That assertion is based on a study carried out on the group’s behalf by WAP Sustainability Consulting.

Bill Ulfelder, the executive director of the Nature Conservancy in New York, said real trees were “unquestionably” the better option. He recommended shopping locally and recycling the tree.

New York City collects trees and uses the mulch in public parks to enrich soil and prevent erosion. Some areas use discarded trees to prevent beach erosion or sink them into lakes to create fish habitats.

Thomas Harman, the founder and chief executive of Balsam Hill, a high-end artificial tree company, said that his factories recycle scrap plastic for use in some components of their products. But manufacturing a recyclable tree has been challenging.

In the meantime, he encouraged people to reuse trees and to adorn them with LED lights, which save energy.

Brad McAllister, a managing director of WAP Sustainability Consulting, said he was surprised by how small the impact of either tree choice was compared with other central elements of the holidays, like air travel and shopping.

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