Connect with us

Ecology

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

Editor

Published

on

[ad_1]

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.

[ad_2]

Source link

قالب وردپرس

Ecology

Today’s letters: ‘Visionary’ plans don’t always work in Ottawa

Editor

Published

on

By

The opinion piece written by Tobi Nussbaum, CEO of the NCC, declares that a “bold, visionary transit plan” would showcase the capital.

As a long-term resident of Ottawa, I’ve had it with visionary plans. In the 1950s, the streetcars serving Ottawa so well were sent to the scrapyards. In the early ’60s, Queensway construction bulldozed established neighbourhoods and ripped the city apart. Later in the decade, the downtown railway station, which could have formed the hub of a commuter network, was relocated to the suburbs. These actions, in the name of “progress,” were undertaken with the “vision” to make Ottawa a car-reliant city.

Now we have an LRT, built just in time for most people to realize that they do not have to go downtown as they can work from home.

Current thinking is pushing a new “link” between Ottawa and Gatineau, with yet more expensive and disruptive infrastructure projects being touted, including a tramway or another tunnel under the downtown core.

Continue Reading

Ecology

That was then: Biggest earthquake since 1653 rocked Ottawa in 1925

Editor

Published

on

By

A regular weekly look-back at some offbeat or interesting stories that have appeared in the Ottawa Citizen over its 175-year history. Today: The big one hits.

The Ottawa Senators were playing a Saturday night game against the Montreal Canadiens at the Auditorium, the score tied 0-0 halfway through the second period. Sens’ rookie Ed Gorman and the Habs’ Billy Boucher had just served penalties for a dustup when the building began to make “ominous creaking sounds.” A window crashed to the ground.

Nearby, at Lisgar Collegiate, all eyes were on teenager Roxie Carrier, in the role of Donna Cyrilla in the musical comedy El Bandido. She had the stage to herself and was singing “Sometime” when the building rocked, the spotlight went out, and someone in the audience yelled “Fire!”

At a home on Carey Avenue, one woman’s normally relaxed cat suddenly arched its back, rushed around the room two or three times, spitting angrily, and climbed up the front-window curtains.

Continue Reading

Ecology

Ottawa delays small nuclear reactor plan as critics decry push for new reactors

Editor

Published

on

By

TORONTO — Canadians will have to wait a little while longer to see the federal government’s plan for the development of small nuclear reactors, seen by proponents as critical to the country’s fight against global warming.

Speaking at the opening of a two-day virtual international conference on Wednesday, the parliamentary secretary to the minister of natural resources said the plan will lay out key actions regarding the reactors. Its launch, Paul Lefebvre said, would come in the next few weeks.

“We’re still putting the finishing touches on it,” Lefebvre said. “The action plan is too important to be rushed.”

Small modular reactors — SMRs — are smaller in size and energy output than traditional nuclear power units, and more flexible in their deployment. While conventional reactors produce around 800 megawatts of power, SMRs can deliver up to 300 megawatts.

Proponents consider them ideal as both part of the regular electricity grid as well as for use in remote locations, including industrial sites and isolated northern communities. They could also play a role in the production of hydrogen and local heating.

“SMRs will allow us to take a bold step of meeting our goal of net-zero (emissions) by 2050 while creating good, middle class jobs and strengthening our competitive advantage,” said Lefebvre.

Natural Resources Minister Seamus O’Regan had been scheduled to speak at the conference but did not due to a family emergency.

Industry critics were quick to pounce on the government’s expected SMR announcement. They called on Ottawa to halt its plans to fund the experimental technology.

While nuclear power generation produces no greenhouse gas emissions, a major problem facing the industry is its growing mound of radioactive waste. This week, the government embarked on a round of consultations about what do with the dangerous material.

Dozens of groups, including the NDP, Bloc Quebecois, Green Party and some Indigenous organizations, oppose the plan for developing small modular reactors. They want the government to fight climate change by investing more in renewable energy and energy efficiency.

“We have options that are cheaper and safer and will be available quicker,” Richard Cannings, the NDP natural resources critic, said in a statement.

Lefebvre, however, said the global market for SMRs is expected to be worth between $150 billion and $300 billion a year by 2040. As one of the world’s largest producers of uranium, Canada has to be part of the wave both for economic and environmental reasons, he said.

“There’s a growing demand for smaller, simpler and affordable nuclear technology energy,” Lefebvre said.

Joe McBrearty, head of Canadian Nuclear Laboratories, told the conference the company had signed a host agreement this week with Ottawa-based Global First Power for a demonstration SMR at its Chalk River campus in eastern Ontario. A demonstration reactor will allow for the assessment of the technology’s overall viability, he said.

“When talking about deploying a new technology like an SMR, building a demonstration unit is vital to the success of that process,” McBrearty said. “Most importantly, it allows the public to see the reactor, to kick the tires so to speak, and to have confidence in the safety of its operation.”

Continue Reading

Chat

Trending