Lesser known ozone layer’s outsized role in planet warming

Ozone is a gas composed of three oxygen atoms. Many studies have described ozone in the stratosphere, and its role in shielding people from the sun’s harmful ultraviolet radiation. Closer to ground level, in the troposphere, ozone is harmful to humans.

New research led by UC Riverside scientists reveals this lower level ozone is adding a great deal of heat to the Southern Ocean — more than scientists previously understood.

This finding has now been published in the journal Nature Climate Change.

Oceans remove a majority of the carbon and heat that enter the atmosphere when humans burn fossil fuels. The Southern Ocean, also called the Antarctic Ocean, collects a third of all excess carbon in the world’s atmosphere, and an estimated 75% of the excess heat collected by the world’s oceans.

Historically, about a third of the ocean’s warming is attributable to ozone. For this third, about 40% is from the stratosphere, and the rest is troposphere.

Volatile organic compounds, or VOCs, from products like pesticides, tobacco smoke and automobiles are gases that form the building blocks of tropospheric ozone. The same is true

— source University of California – Riverside | Apr 22, 2022

Nullius in verba


Ice shelf collapses in previously stable East Antarctica

An ice shelf the size of New York City has collapsed in East Antarctica, an area long thought to be stable and not hit much by climate change, concerned scientists said Friday. Satellite photos show the area had been shrinking rapidly the last couple of years, and now scientists wonder if they have been overestimating East Antarctica’s stability and resistance to global warming that has been melting ice rapidly on the smaller western side and the vulnerable peninsula. The ice shelf, about 460 square miles wide (1200 square kilometers) holding in the Conger and Glenzer glaciers from the warmer water, collapsed between March 14 and 16.

— source abcnews.go.com | 25 Mar 2022

Nullius in verba


How plants respond to heat stress

It may be hard to remember in winter, but July 2021 was the hottest month ever documented. In the USA, the mean temperature was higher than the average for July by 2,6 degrees Fahrenheit, and many southern European countries saw temperatures above 45 degrees Celsius including an all-time high temperature of 48,8 degrees Celsius recorded on the eastern coast of Sicily in Italy.

The past few decades have seen an increased incidence of heat waves with record highs around the globe, and this is seen as a result of climate change. Heat waves have been occurring more frequently, have been hotter, and have been lasting longer with severe consequences not only for humans and animals but also for plants. “Heat stress can negatively affect plants in their natural habitats and destabilize ecosystems while also drastically reducing crop harvests, thereby threatening our food security,” says Brigitte Poppenberger, Professor for Biotechnology of Horticultural Crops.

Cells activate a molecular defense pathway for heat stress protection

To survive short periods of heat stress, plants activate a molecular pathway called the heat-shock response. This heat-shock response (common to all organisms) protects cells

— source Technical University of Munich (TUM) | Jan 4, 2022

Nullius in verba


Ranking the reasons why the Larsen C ice shelf is melting

Scientists know the surface of the Larsen C ice shelf in Antarctica is melting, making it vulnerable to collapse. For the first time, we can rank the most important causes of melting over the recent past.

In a new two-part paper in Journal of Geophysical Research: Atmospheres, we show how the amount of energy reaching the ice from the sun is the dominant factor, followed by warm winds, clouds and weather patterns. These drivers of melting can interact and overlap to reinforce or counteract each other, so it is a complex picture.

Understanding what is causing melting over Larsen C is vital as it will help predict the future of the ice shelf, which will have knock-on consequences for sea levels worldwide.

In 2002, Larsen C’s neighbouring ice shelf, Larsen B, experienced melting so severe that it eventually caused the shelf to collapse completely.

— source skepticalscience.com | 20 Apr 2022

Nullius in verba


What the latest science says about Antarctica and sea-level rise

As the Earth’s climate warms, sea levels are rising, threatening to swallow coastlines and flood low-lying cities. Scientists are working to understand how much and how quickly seas could rise in coming decades – and Antarctica is one wild card.

Here are some of scientists’ most important findings from 2021 about the changes occurring in and around the world’s coldest continent.

What happens if Antarctica melts?

More than 97% of Antarctica is covered in ice. With a depth of up to three miles, the continent’s 6 million cubic miles of ice contain 70% of Earth’s fresh water. If all of that ice melted, the world’s oceans would rise by 200 feet (61 meters), enough to inundate Tokyo, New York City, Shanghai, and other cities.

How much the Earth’s average temperature rises is one of the main factors that will determine how Antarctic melting plays out. The climate has already warmed by roughly 1 degree Celsius (1.8 degrees Fahrenheit) since the late 1800s.

— source skepticalscience.com | 7 Mar 2022

Nullius in verba


Methane emissions are 70% higher than reported

Methane emissions from the oil, gas, and coal industries are 70 percent higher than official government estimates around the world, according to the International Energy Agency’s latest methane report released Wednesday. As demand for energy rebounds from its COVID-19-induced slump in 2020, the report highlights the need for improved methane monitoring and plugging leaks — fast.

Oil and gas companies churn out around 40 percent of human-produced methane. The invisible, odorless gas issues from pipelines, oil and gas wells, and the lines that shuttle gas into homes. Using the latest data from satellites and other measurement efforts, the IEA, a Paris-based energy watchdog, uncovered significant discrepancies between government figures and the reality of methane leaks.

Tackling methane is one of the best ways to keep global warming in check, the report says, and with gas prices hitting record highs, oil and gas companies could even profit by

— source grist.org | Lina Tran | Feb 24, 2022

Nullius in verba


Ford and GM knew about climate change — and covered it up for decades

Exxon knew, Shell knew, coal knew — is it any surprise that top auto manufacturers knew, too?

A new investigation from E&E News revealed that Ford and General Motors knew as early as the 1960s that car emissions caused climate change. Scientists at both companies were “deeply and actively engaged” in research linking their products to global warming, according to Carroll Muffett, president and CEO of the Center for International Environmental Law, which obtained hundreds of company documents for the report. And yet despite this information,GM and Ford spent decades eschewing electric vehicles and doubling down on gas-guzzling SUVs. They financed climate denial groups who worked to block international climate agreements and opposed stricter U.S. emissions standards.

E&E News’ five-month-long investigation into the automakers’ knowing climate culpability is the latest in a long list of corporate environmental cover ups. In 2015, reporting

— source grist.org | Joseph Winters | Oct 27, 2020

Nullius in verba


Mountain glaciers may hold less ice than previously thought

Mountain glaciers are essential water sources for nearly a quarter of the global population. But figuring out just how much ice they hold — and how much water will be available as glaciers shrink in a warming world — has been notoriously difficult.

In a new study, scientists mapped the speed of over 200,000 glaciers to get closer to an answer. They discovered that widely used estimates of glacier ice volume may be off by about 20 per cent in terms of how much Earth’s glaciers outside the Greenland and Antarctic ice sheets could contribute to sea level rise.

Mathieu Morlighem, a leader in ice sheet modeling and a coauthor of the study, explains why the new results hold a warning for regions that rely on glaciers’ seasonal meltwater, but barely register in the big picture of rising seas.

— source theconversation.com | Mathieu Morlighem | 08 Feb 2022

Nullius in verba


The ramifications of ocean acidification for coralline algae

Scientists have long suspected that coralline algae are particularly sensitive to changes in ocean chemistry. Now, researchers have found that most species of coralline algae studied are negatively affected by ocean acidification.

In a new study published in Global Change Biology, an international team, including researchers from the University of Tsukuba, revealed that lower seawater pH is associated with decreases in the abundance, calcification rates, and recruitment of coralline algae. As levels of carbon dioxide increase in the atmosphere, larger amounts are absorbed by the oceans. The resulting changes in ocean chemistry spell trouble for calcifying species like corals and coralline algae.

Coralline algae are critical species in shallow marine ecosystems globally. By creating calcium carbonate skeletons, these algae act as “cement” for reef systems and provide new substrate for corals and other organisms to settle on. With ocean acidification, less carbonate is available to build these skeletons.

The effects of ocean acidification on different species of coralline algae have been studied for a number of years but the overall outlook for these species is unclear. The team reviewed all available studies on coralline algae and ocean acidification and used a variety of methods to tease out overall patterns.

— source University of Tsukuba | Nov 4, 2021

Nullius in verba