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Research showing steeper increases in ocean heat is not exactly new. So what’s up with all those headlines?

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There’s been good evidence that the oceans were heating up faster than thought. Now, scientists have fitted the puzzle pieces together.

The trend in the amount of ocean heat is shown for the period 1993 to 2015. Yellow, orange and red tones show locations where ocean heat has increased. (Source: Cheng, Lijing & NCAR. Last modified 10 May 2017. "The Climate Data Guide: Ocean temperature analysis and heat content estimate from Institute of Atmospheric Physics." Retrieved from https://climatedataguide.ucar.edu/climate-data/ocean-temperature-analysis-and-heat-content-estimate-institute-atmospheric-physics.)

The trend in the amount of heat in the oceans is shown for the period 1993 to 2015. Yellow, orange and red tones show locations where ocean heat has increased. (Source: Lijing Cheng & NCAR. Retrieved from https://climatedataguide.ucar.edu/climate-data/ocean-temperature-analysis-and-heat-content-estimate-institute-atmospheric-physics.)

So this morning, as I’m drinking my coffee and perusing news headlines, I see this in the New York Times: “Ocean Warming Is Accelerating Faster Than Thought, New Research Finds.”

The story was about a new paper published Thursday in the journal Science titled, “How fast are the oceans warming?”

This is a big deal, because human-caused global warming doesn’t affect just the land surface. In fact, more than 90 percent of global warming’s heat is absorbed in the oceans. That has helped prevent much steeper increases in temperature on land.

But all that heat going into the oceans isn’t really a benign phenomenon. By causing ocean waters to expand, it contributes to sea level rise. The heat also can make storms more destructive, and it’s putting enormous stress on ocean ecosystems — which we depend on heavily for food.

And in the long run, what goes into the oceans doesn’t all stay in the oceans. Heat eventually comes out of the water to contribute to warming atmospheric temperatures around the globe.

So knowing exactly how much heat is going in is very important. With that in mind, I checked out other stories about the new paper in Science, and I saw that many featured similar headlines as the N.Y. Times.

More about the scientific paper in a minute. But first, I have to say that I realized I had seen very similar headlines before. Just this past October, for example, I saw this in Scientific American: “The Oceans Are Heating Up Faster Than Expected.” According to the story, a “new study published yesterday in the journal Nature concluded that the global oceans may be absorbing up to 60 percent more heat since the 1990s than older estimates had found.”

And nearly two years ago, the Washington Post ran this headline: “The world’s oceans are storing up staggering amounts of heat — and it’s even more than we thought.”  That was based on a study published in the journal Science Advances. In a press release about it, study co-author Keven Trenberth of the National Center for Atmospheric Research was quoted as saying that “the planet is warming quite a lot more than we thought.”

Hmmm. Two years ago we already knew that the planet was warming quite a lot more than we thought. So what’s up with today’s headlines, which seem to suggest that we didn’t know this?

For quite awhile now, scientists have actually had good reasons to believe the oceans have been taking up more global warming heat than was estimated in a major report in 2014 from the U.N.’s Intergovernmental Panel on Climate Change. And more recently, research has been confirming those suspicions.

If you read beyond the headline and down into that New York Times story — which actually is quite good — you’ll see that the new paper isn’t at all a research article presenting a major new advance. It’s actually an assessment based on previous original research of the state of knowledge about rising ocean heat content, or “OHC,” as scientists label it. And as the assessment concludes, “Multiple lines of evidence from four independent groups thus now suggest a stronger observed OHC warming.”

Based on a lot of the coverage I encountered today, you might easily conclude that the new assessment produced dramatic new findings. But the findings have actually been piling up for a few years — as have those headlines, some of them quite dramatic. Now, the authors of the new assessment have pulled multiple strands of previous research together to provide a clearer picture of what’s currently known.

That picture shows that the oceans are heating up 40 percent faster than what the U.N. report estimated. And things are getting increasingly worse. As Trenberth, one of the authors, put it in an email to me today, “There are clear signs of acceleration.”

The better estimates of how much global warming heat is going into the oceans is based in part on new ways of piecing together data from different sources. Since the early 2000s, accurate data have been provided by a modern network of floating ocean heat sensors, called the Argo network. But prior to that, information was collected by less accurate sensors called expendable bathythermographs.

Because of inaccuracies, the data from the older sensors contained biases. Thanks to recent research, scientists have found ways to deal with this issue, providing a better picture of just how much more heat the oceans have been sopping up compared to the past.

The picture has also been improved by new ways of dealing with another vexing issue: In the past, larger portions of the oceans went unmonitored than today. “The oceans are not well observed as we go back in time,” notes Trenberth.

In the past, scientists tried to deal with this using various strategies for filling the gaps. But these tended to produce overly conservative estimates. More recently, satellite observations and computer modeling have helped improve estimates of  what has been going on in largely unmonitored areas of the oceans.

And still other researchers have analyzed ocean factors that are influenced by ocean temperature to derive independent estimates of how the ocean’s store of heat  has changed over time.

Overall, the estimates derived by these studies are in line with what climate models have been saying. The models have tended to indicate more ocean warming than what had been observed, and that discrepancy had given fodder for critics of climate change science. But now, Trenberth and his fellow authors say that discrepancy is largely gone.

One of the sobering conclusions of the new assessment is the likely consequences of failing to get off the business-as-usual scenario of high emissions of heat-trapping greenhouse gases. Model projections — which we now know have been line with observations — show that the likely amount of ocean warming “would have major impacts on ocean ecosystems and sea level rise through thermal expansion,” the scientists write.

When you combine estimates of thermal expansion with projected sea level rise from melting glaciers and ice sheets, you come up with numbers that “portend very bad consequences for many coastal regions,” Trenberth told me in an email message.

My point in writing all of this today is to point out that if you pay too close attention to headlines, you might get the impression that science happens in discrete bursts of dramatic new research findings. In fact, most of the time, research progresses incrementally, with different groups of scientists probing at a particular issue independently and often in different ways. One study usually doesn’t provide definitive insight into a phenomenon. It takes multiple findings — and sometimes a group of scientists fitting those puzzle pieces together — to produce a clearer, convincing picture.

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Ecology

Globe Climate: Canada’s resource reckoning is coming

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Good afternoon, and welcome to Globe Climate, a newsletter about climate change, environment and resources in Canada.

This afternoon, the Alberta government announced that it is restoring a coal mining policy it revoked last spring. At the time, the move provoked a widespread public backlash detailed by The Globe. The original decision, which opened up more than 1.4 million hectares to exploration, was made without public consultation. Premier Jason Kenney previously defended the changes.

Lots more on coal and Canada’s resources industry in this week’s newsletter edition.

Now, let’s catch you up on other news.

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Ecology

‘Incredibly destructive’: Canada’s Prairies to see devastating impact of climate change

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As the climate continues to warm at an alarming rate, experts warn if dramatic steps to mitigate global warming are not taken, the effects in Canada’s Prairie region will be devastating to the country’s agriculture sector.

According to Environment and Climate Change Canada, the country is warming, on average, about double the global rate.

Scientists with the National Oceanic and Atmospheric Administration in the U.S. recently found 2020 was earth’s second-hottest year on record, with the average land and ocean surface temperature across the globe at 0.98 of a degree C above the 20th-century average.

However, the agency found the northern hemisphere saw its hottest year on record, at 1.28 degrees C above the average.

“(In Canada) we are looking at about 6.4C degrees of warming this century, which isn’t much less than one degree per decade, which is just a terrifying rate of warming,” Darrin Qualman, the director of climate crisis policy and action at the National Farmer’s Union said.

Qualman said there is “massive change coming” to Canada’s Prairies, which will be “incredibly destructive.”

“It’s not going too far to say that if we made that happen, parts of the Prairies wouldn’t be farmable anymore,” he said.

According to the federal government, in 2018 Canada’s agriculture and agri-food system generated $143 billion, accounting for 7.4 per cent of the country’s GDP.

The sector employed 2.3 million people in 2018. The majority of the 64.2 million hectares of farmland in Canada is concentrated in the Prairies and in southern Ontario.

The effects of climate change are already being felt on the ground in the Prairies, Qualman said, adding that the NFU has already heard from farmers complaining of “challenging weather.”

“People are sharing pictures of flattened crops and buildings, et cetera, that have been damaged,” he said. “And we’re still at the beginning of this.”

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Ecology

Insect-based dog food aims to cut your pet’s carbon pawprint

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Meat has an enormous carbon footprint, with livestock liable for about 15 per cent of worldwide emissions, as we have beforehand mentioned on this e-newsletter. That is prompted specialists to suggest consuming much less meat for sustainability (and well being) causes.

However what about your pet? One research discovered that the methane and nitrous oxide emissions generated by canine and cat meals within the U.S. alone had been equal to about 64 million tonnes of CO2, or roughly the quantity produced by 13.6 million automobiles. And it might be getting worse, with a development towards feeding pets “human-grade” meat.

That is prompted some pet meals makers to look to lower-carbon protein sources — together with bugs.

Research present that producing insect-based meals requires far much less feed, land and water and generates far fewer greenhouse fuel emissions per kilogram than meats comparable to beef, pork or rooster.

That is one of many causes increasingly more pet meals containing insect protein are hitting the market. Purina, a model owned by multinational Nestlé, launched a line of canine and cat meals containing black soldier fly larvae in Switzerland in November.

In Canada, Montreal-based Wilder Harrier began promoting canine treats made with cricket protein in 2015 and pet food made with black soldier fly larvae in 2019. It plans to broaden to launch a line of insect-based cat treats later this yr and cat meals in 2022 due to “a ton of demand,” mentioned firm co-founder Philippe Poirier.

Wilder Harrier initially labored with animal nutritionists on insect-based merchandise to unravel a unique downside — specifically, the founders’ canines had allergy symptoms to frequent meats utilized in canine meals. Poirier mentioned now about half its prospects hunt down the product due to their pets’ allergy symptoms and about half for environmental causes.

Dr. Cailin Heinze, a U.S.-based veterinary nutritionist licensed by the American School of Veterinary Vitamin, has written concerning the environmental influence of pet meals. She mentioned we’re typically “not as involved as we probably ought to [be]” concerning the environmental footprint of pets.

Alternatively, she famous that the longer-term influence of newer diets, comparable to vegan meals and people containing bugs, hasn’t been nicely examined in comparison with conventional pet meals.

Maria Cattai de Godoy, an assistant professor of animal sciences on the College of Illinois who research novel proteins for pet meals (together with bugs, yeast and plant-based substances), mentioned such substances are rigorously examined to find out their security and diet earlier than being added to pet meals. 

“This can be a very extremely regulated trade,” she mentioned, however admitted it is also evolving.

Relating to bugs, she mentioned constructive information “reveals promise in direction of utilizing them increasingly more in pet meals.” Insect-based proteins have additionally earned the endorsement of the British Veterinary Affiliation, which says some insect-based meals could also be higher for pets than prime steak.

However Godoy famous that there isn’t any one-size-fits-all resolution, and pet homeowners ought to take into consideration the wants of their very own particular person pet and analysis whether or not a specific weight loss plan can be appropriate.

She mentioned that other than the kind of protein, issues like packaging and manufacturing strategies may also make a distinction. For instance, utilizing meat byproducts that may in any other case turn into waste would not drive elevated meat manufacturing the identical approach as utilizing human-grade meat.

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