Connect with us

Ecology

In the Blink of an Eye, We’re Turning Back the Climatic Clock by 50 Million Years

Editor

Published

on

[ad_1]

This animation based on computer modeling shows what climatic conditions will look like out to the year 2280 if we emissions of greenhouse gases are not restrained. The color coding shows how future conditions would compare to climates of the past. (Source: "Pliocene and Eocene provide best analogs for near-future climates," K. D. Burke et al, Proceedings of the National Academy of Sciences Dec 2018, 201809600; DOI: 10.1073/pnas.1809600115)

This animation depicts climatic conditions out to 2280 assuming emissions of greenhouse gases are not restrained. The color coding shows how future conditions would compare to past climates, with lighter orange corresponding to the Pliocene Epoch about 3 million years ago, and darker orange to the Eocene about 50 million years ago. Dark red indicates future climatic conditions with no past analog. (Source: “Pliocene and Eocene provide best analogs for near-future climates,” K. D. Burke et al, Proceedings of the National Academy of Sciences Dec 2018, 2018)

Absent serious action on climate change, we’ll continue careening toward a climatic cliff. And modern civilization will be hard-pressed to survive the plunge.

This is the essential take-away from new research probing Earth’s climatic past to yield insights into our future. The research finds that if our emissions of carbon dioxide and other greenhouse gases continue unabated, Earth’s climate will warm by the year 2150 to levels not seen since the largely ice-free Eocene Epoch about 50 million years ago.

That may seem like a long time on a human timescale. But consider that the research shows we’re currently on course to reversing 50 million years of cooling in just a couple of centuries. That may be so rapid that it will outpace our ability to adapt our agricultural and other modern life support systems.

Thanks to our emissions of greenhouse gases, “the Earth system is well along on a trajectory to a climate state different from any experienced in our history of agricultural civilizations,” write Kevin Burke and his co-authors in a paper published in the Proceedings of the National Academy of Sciences.

Here’s why that’s troubling: Modern human civilizations, made possible by agriculture, have thrived in what scientists term “a safe operating space,” meaning a stable, relatively benign climate. But now, staying within that safe space seems to be “increasingly unlikely,” the researchers write.

“If we think about the future in terms of the past, where we are going is uncharted territory for human society,” says the study’s lead author, Kevin Burke, in a press release. Burke led the research while he was a graduate student in the lab of paleoecologist John “Jack” Williams of the University of Wisconsin-Madison.

“We are moving toward very dramatic changes over an extremely rapid time frame, reversing a planetary cooling trend in a matter of centuries,” Burke says.

Temperature trends for the past 65 million years and potential geohistorical analogs for future climates. Red arrows show six geohistorical states of the climate system: Paleocene, Miocene, Oligocene, TK, TK and TK. A time series showing global mean annual temperatures is also shown. Major patterns include a long-term cooling trend, periodic fluctuations driven by changes in the Earth’s orbit, and recent and projected warming trends. Temperature anomalies are relative to 1961–1990 global means. (Source: TKTK

Temperature trends for the past 65 million years and potential past analogs for future climates. Red arrows show  “geohistorical” states of the climate system. From the left, these are the early Eocene Epoch; the mid-Pliocene; the last interglacial, or LIG; the mid-Holocene; the pre-industrial period; the historical period; and projections for the future (at extreme right). The time series shows how global mean annual temperatures departed from the 1961 to 1990 mean. Major patterns include a 50-million-year cooling trend beginning in the Eocene, periodic fluctuations driven by changes in the Earth’s orbit, the recent warming caused by human activities, and projected warming. (Source: “Pliocene and Eocene provide best analogs for near-future climates,” K. D. Burke et al, Proceedings of the National Academy of Sciences Dec 2018, 2018)

To conduct the research, Burke and his colleagues compared climatic conditions of several periods in geologic history with computer model projections of the future. These projections assumed different greenhouse gas emission scenarios.

One sobering finding was that we are already headed toward a climatic state like that of the mid-Pliocene Epoch about 3 million years ago even if we do manage to reduce our emissions of greenhouse gases. In fact, thanks to burning of fossil fuels and other human activities, carbon dioxide concentrations in the atmosphere are already at Pliocene levels: more than 400 parts per million. We just don’t have a Pliocene-like climate yet because most of the planet’s surface is covered in oceans — and all that water takes time to warm up.

The research shows that if we undertake moderate emissions reductions, we’ll stabilize at Pliocene-like temperatures by 2040. During the Pliocene, temperatures were between 3.2 and 6.5 degrees Fahrenheit (1.8 to 3.6 degrees Celsius) warmer than they are today.

At their peak, sea level during the Pliocene stood 72 feet (22 meters) higher than today. Luckily, inertia in the climate system means that it would take a few centuries before sea level would come up to that level again. (Looking at past climates, scientists have documented maximum rates of sea level rise of three to five meters per century.)

Even so, Pliocene-like temperatures should bring a host of climate impacts that will prove challenging for modern societies to adapt to. And over time, we’ll have to deal with that Pliocene-like sea level rise.

“There is a very good relationship between sea level and temperature on the planet,” says James White, a paleoclimatologist at the University of Colorado who was not involved in the current research. “If you warm up air, and you warm up water, you melt ice. And when land ice melts and goes into the ocean, you raise sea level.”

The 20 meters of sea level rise that correspond to a Pliocene-like climate “is enormous,” White says. It would submerge coastal cities around the globe which are currently home to many tens of millions of human beings.

The silver lining is that by reducing carbon emissions, we’d at least stabilize climatically without things getting even more challenging. But if we don’t reduce our emissions, the planet will continue to warm — quite dramatically.

By the year 2150, Earth’s average temperature would rise by a staggering 23 degrees Fahrenheit (13 degrees Celsius) above current conditions, taking them to Eocene-like levels. During that geologic epoch, there was no permanent ice on the planet, and sea level is estimated to have been at least 100 meters higher than today.

If we follow this path, the rapid change we’d trigger would be without precedent during the entire Cenozoic Era, the age of mammals, which began about 65 million years ago when the dinosaurs went extinct.

“What the planet’s going to do is very predictable,” White observes. Basic physics plus research on past climatic states provides confidence that “temperatures will rise, sea level will go up, and storms will get worse. It’s all very predictable. What’s not is how we will respond.”

I don’t know about you, but I’d prefer to respond in a way that would leave us in the Pliocene, not the Eocene.

[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