Lethal Heating: 07/16/20

16/07/2020

Larger Waves In Store As The Planet Warms

Eos - Katherine Kornei

By the end of the 21st century, waves will have gotten larger in some ocean basins, particularly the Southern Ocean, climate modeling reveals.

The Southern Ocean, which skirts Antarctica, may experience larger waves as the climate warms. Credit: Mike Hill/Stone/Getty Images

Life-sustaining. Beautiful. Destructive.

Ocean waves are all of those—they transport nutrients that nourish marine life, but they also damage ships and batter coastlines, triggering erosion that can send homes and roads tumbling.

Now, scientists have used climate models to show that some parts of the globe, including the Southern Ocean, are likely to experience larger waves by the end of the 21st century.

That’s potentially bad news for coastal residents, the researchers suggest, because large waves could generate increased flooding and erosion.

Generated by Wind

Ocean waves are kicked up by the wind, and warmer conditions promote stronger winds. Larger waves might therefore be a hallmark of our planet’s future, Alberto Meucci, an oceanographer at the University of Melbourne in Australia, and his colleagues hypothesized. They set out to test that idea using climate models.

The researchers focused on a metric known as significant wave height. Defined as the average of the highest one third of waves, it’s a commonly used parameter in oceanography. (Waves more than twice the significant wave height are called rogue waves. These watery monsters, which can top 25 meters, were dismissed as sailors’ tall tales for years before they were finally recorded using modern instruments.)

Many Climate Models

Meucci and his collaborators relied on two very different greenhouse gas emission scenarios.

One, Representative Concentration Pathway (RCP) 8.5 (the “business-as-usual” scenario), which assumes that carbon emissions will remain largely uncurbed, yields 8.5 watts per square meter of additional warming by the end of the 21st century (about 4.3°C). The other, RCP 4.5, assumes that some emissions mitigation policies are enacted and yields about 2.4°C of warming by 2100.

The researchers input both scenarios into seven different climate models. Meucci and his colleagues used multiple climate models to beat down statistical uncertainties. “The point of using seven global climate models instead of a single model was to be able to reduce the uncertainties connected with the representation of extremes,” said Meucci.

The novelty of this study is its use of multiple climate models, said Laure Zanna, a physical oceanographer at New York University not involved in the study. “If you want to be able to predict changes in extremes, having enough data to do so is important.”

Meucci and his collaborators fed the surface wind outputs of the climate models into wave generation models.

The scientists determined the 1-in-100-year significant wave height—corresponding to a wave that has a 1% probability of occurring each year—for both the RCP 8.5 and RCP 4.5 scenarios for two time periods: 1979–2005 and 2081–2100.

The scientists found an increase in the 1-in-100-year significant wave height at the end of the 21st century in the Southern Ocean for both greenhouse gas emission scenarios.

The largest difference, roughly 15%, was observed in the Southern Ocean for the RCP 8.5 scenario.

Larger waves might spell bad news for this region, which is already routinely battered by waves topping 20 meters, the team concluded.

Large swells could very well roll up on the coasts of South Africa, South America, and Australia, said Meucci, where they might contribute to flooding and coastal erosion. Their impact could also be more far-reaching, he said. “Changes may be felt up to the North Pacific.”

But not all ocean basins will experience larger waves, the team found. In portions of the North Atlantic, wave height might even decrease by the end of the 21st century, Meucci and his collaborators noted.

The researchers next investigated changes in the frequency of extreme waves. Again, the Southern Ocean stood out. That basin was more likely to experience large waves at the end of the 21st century compared with 1979–2005, the team found.

These findings are believable, but it’s important to pinpoint what’s driving the changes in the Southern Ocean, said New York University’s Zanna. “An understanding of the physical mechanisms would help strengthen even further their results.”

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(US) Joe Biden Unveils Aggressive $2tn Climate And Jobs Plan

The Guardian - Emily Holden

Proposal outlines $2tn for clean energy infrastructure and climate solutions, to be spent as quickly as possible in next four years

Joe Biden speaks during a campaign event in Wilmington, Delaware, on 14 July. Photograph: Patrick Semansky/AP

Joe Biden has unveiled a new, more aggressive climate and jobs plan which advisers say he would take to Congress “immediately”, if elected president.

The new proposal outlines $2tn for clean energy infrastructure and other climate solutions, to be spent as quickly as possible in the next four years, what would be the Democrat’s first term in office. Last year, he proposed $1.7tn in spending over 10 years.

“Addressing the economic crisis is going to be priority one for a President Biden,” a senior campaign official told reporters. “This will be the legislation he goes up to [Capitol Hill] immediately to get done. The reality is we will be facing a country that will be in dire need of these types of investments that are going to be made here.”

Two crises are converging: a devastated economy and high unemployment that could drag on for years as the nation struggles to gain control of the coronavirus pandemic, and a rapidly closing window to significantly cut heat-trapping emissions and lead on global climate action.

Biden unveiled the climate plan, the second part of his “Build Back Better” proposal, in remarks from Delaware on Tuesday afternoon.

“When Donald Trump thinks about climate change, the only word he can muster is ‘hoax’,” Biden said, referring to Trump’s previous claims that the crisis is fake. “When I think about climate change, the word I think of is ‘jobs’.”

In a detailed climate policy speech, Biden said his proposal would create a million jobs in electric vehicle manufacturing, a million in upgrading buildings and a quarter-million cleaning up after extractive industries.

Biden said he would give Americans money back for switching to cleaner cars and making their homes more efficient.

He said he was focusing on his first four years as president because “science tells us we have nine years before the damage is irreversible”.

The new goals align Biden more closely with three primary opponents, the Vermont senator Bernie Sanders, the Massachusetts senator Elizabeth Warren and Jay Inslee. the Washington governor.

They follow the recommendations of a unity taskforce of Sanders and Biden supporters that was co-chaired by the New York congresswoman Alexandria Ocasio-Cortez, who co-sponsored the Green New Deal.

Biden staffers painted a picture of a modernized America with the “cleanest, safest, fastest rail system in the world”, the biggest electric vehicle manufacturing sector, 4m upgraded buildings and 1.5m new sustainable homes and public housing units. They pitched the spending as a jobs plan as much as a climate program.

The blueprint aims for a clean electricity system including renewable power and nuclear energy by 2035. Biden would not ban fracking for natural gas, which would require an act of Congress. But he would prohibit new fracking on public lands.

Gina McCarthy, the former Environmental Protection Agency administrator who is now president of the Natural Resources Defense Council Action Fund, said the plan was “by a long shot – the most ambitious we have ever seen from any president in our nation’s history”.

Labor unions and environmental justice communities would be central to climate efforts, campaign staffers said. Climate change hits low-income and communities of color hardest, a background document noted.

Biden would create a national crisis strategy to ensure that government responses to disasters are equitable, start a taskforce to decrease climate risks for the most vulnerable, and establish an office of climate change and health equity.

The faster timeline is meant to ensure that no future president can reverse climate gains, in the way Donald Trump’s administration has boosted fossil fuels.

Trump plans to exit the Paris climate agreement but Biden has vowed to re-enter it and double down on US contributions.

Much of Biden’s plan would require agreement from Congress. Gaining control of the Senate is critical.

“He is confident he will be able to work with Congress to get something constructive done,” the senior campaign official said. “He is of course at the same time making sure that he is campaigning in every state needed to make sure that we win every Senate seat we possibly can to further that goal.”

Another Biden official said the program would be funded by tax increases for corporations and “asking the wealthiest Americans to pay their fair share”.

The updated climate plan follows Biden’s announcement last week of a $700bn “buy American” proposal to revive US manufacturing.

Varshini Prakash, co-founder of the youth-led Sunrise Movement, said Biden’s revised plan responds to many of the group’s previous criticisms by “dramatically increasing the scale and urgency of investments, filling in details on how he’d achieve environmental justice and create good union jobs, and promising immediate action — on day 1, in his first 100 days, in his first term, in the next decade — not just some far off goals”.

Trump campaign spokesman Hogan Gidley claimed Biden’s plan would kill 10m American energy industry jobs and called it a “socialist manifesto”.

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Record Locust Swarms Hint At What’s To Come With Climate Change

Eos - Rina S. Khan

Warming oceans that feed cyclones have also bred record-breaking swarms of desert locusts. Such plagues could grow bigger and more widespread with climate change.

The locust attacks of 2019–2020 are the worst of the past 30 years. Credit: Sarwar Panhwar

In mid-June, the United Nations Food and Agriculture Organization (FAO) issued a threat level warning to countries across East Africa and southwest Asia: Desert locusts (Schistocerca gregaria) are swarming.

A severe outbreak that started in 2019 has spread across the Horn of Africa and the Middle East before moving on to western Asia. Scientists say climate change has played a role in this invasion.

Usually solitary, locusts become gregarious, or swarm, when there are heavy rains in an arid region. Desert locust swarms are highly destructive, sparing no greenery in sight.

This year’s locust attacks, which spread from Kenya to Pakistan and India, are the worst in the past 30 years and may be the most economically destructive since the 1960s, said Chaudhry Inayatullah, a former research scientist at the International Centre of Insect Physiology and Ecology in Nairobi, Kenya.

The swarms are expected to peak this month, as a wetter-than-normal monsoon arrives, and to flourish as the rains continue through October.

Inayatullah and other locust experts fear that these attacks will only get worse. Climate change is altering the dynamics of pest control and reproduction, said Keith Cressman, the FAO’s senior locust forecaster. Changes in climate have led to increases in cyclones, which feed locust swarms with water and warmth.

This mango tree in Hyderabad, Pakistan, is devoid of its leaves, which were consumed by a swarm of desert locusts. Credit: Sarwar Panhwar

Recent research also shows that human-induced warming may be intensifying a regional variability in an Indian Ocean pattern of warming and cooling called the Indian Ocean Dipole (IOD), sometimes nicknamed the “Indian Niño.”

A more intense IOD could cause more frequent tropical storms and heavy rains. These rains create perfect conditions for locust breeding, with more water and warmth ideal for increased plant biomass to feed the locusts—which is what happened in 2019, when a record IOD led to above-average rainfall in the coastal areas of Somalia, Yemen, and some regions bordering the Red Sea.

During droughts, locust outbreaks do not occur in the region, mostly because of a lack of plants for the insects to eat. But higher temperatures associated with climate change coupled with increased availability of plants for food could speed up the locusts’ maturation and incubation during spring, Inayatullah said.

This year, warmer temperatures have already allowed an extra generation of breeding to occur in northwest Africa, the Arabian Peninsula, and southwest Asia, amplifying the overall risk of a locust plague, the most serious category of locust threat identified by the FAO.

Perfect Storms for Locusts
“If this trend of increased frequency of cyclones in [the] Indian Ocean continues, then certainly, that’s going to translate to an increase in locust swarms in the Horn of Africa,” said Cressman.

An increased number of cyclones in the past 3 years in the Indian Ocean played a role in the current upsurge. “In 2018, two cyclones dumped heavy rain on the uninhabited portion of the Arabian Peninsula known as the Empty Quarter. There, locusts can breed and reproduce freely.

Three generations of breeding occurred in 9 months in the Empty Quarter, causing locust numbers to increase by 8,000 times.” Cressman said that outbreak is the source of the East Africa upsurge the FAO is warning about now.

The swarms can jump oceans, and they leapt over the Red Sea and Gulf of Aden to the Horn of Africa late last year. “There, another cyclone in December 2019 triggered yet another spasm of reproduction that could give rise to two more generations of breeding—400 times the locusts,” Cressman said.

Climate anomalies have allowed desert locust populations to have “reproductive spasms” several times this year. Credit: Sarwar Panhwar

Heavy rains in Yemen and Saudi Arabia prompted the spread of locusts into Iran and Pakistan.

They have also managed to breed in Pakistan’s Balochistan Province adjacent to Iran, are currently sweeping across the country’s southern agricultural belt, and have entered India across the Rajasthan desert.

Drifting with the wind, some individuals have even been captured in Nepal.

The FAO says the spring-bred swarms along both sides of the Indian-Pakistan border were poised to mature and lay eggs in early July, and new swarms will arrive from the Horn of Africa in mid-July.

Already, some farmers in Pakistan have reported up to 50% losses of their cotton crops.

Ghulam Sarwar Panhwar, who owns two farms on around 120 hectares of land in the Hyderabad District of Sindh, said three locust attacks hit his farm in the past 3 months.

“Each time it is like a black cloud descending from the sky. There are millions of them, and they attack the cotton and other crops, eating all the green leaves in just 3–4 hours’ time before moving on,” Panhwar said. “Half of my cotton crop is gone. We chase them off by beating drums and banging metal plates. What else can we do?”

Aside from eating cash crops, the locusts are also consuming fodder plants, which will affect livestock.

Climate Controls

Meanwhile, the FAO has asked Pakistan and India to remain on high alert. India, Pakistan, Iran, and Afghanistan are all part of FAO’s Commission for Controlling the Desert Locust in South-West Asia. “Intercountry cooperation is needed to tackle the locust threat. Where they fly next depends on wind direction, speed, and other weather parameters,” Inayatullah said.

A farmer holds one locust out of the thousands that have ravaged crops in Pakistan. Credit: Sarwar Panhwar

Accurate wind forecasts could be helpful to understand possible new landing sites, where aerial and ground spraying operations for pesticide applications could be readied in advance.

Spraying in desert breeding areas in Pakistan has been underway since February, the region’s early spring, and could have its own set of ecological impacts.

The locust swarms eventually will dwindle in the cooler and drier winter months.

No longer gregarious, “they will change back to their solitary phase,” Inayatullah said, “but by then they would have spread over vast areas and would have enough fat in them to stay alive even without food—until warmer weather arrives. This would be the ideal time to monitor and control them.”

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