May 15 2023
May 15 2023
The BBC reports that average global ocean temperature has recently spiked to an all-time high. Such a rapid and large increase has never before been recorded, and it will likely have major implications for weather and ocean ecosystems. Wired notes that temperatures that used to be described as marine heatwaves have become normal, as greenhouse gases are adding more and more heat to the ocean every year. A warmer Southern Ocean is a key reason that Antarctic ice melt is accelerating.
Yale e360 reports on an important new study modeling the change of ice formation in the Southern Ocean, which has profound implications for global ocean circulation. With less ice forming in the ocean, and more freshwater entering coastal areas from glacial melt, surface water in the Southern Ocean and around Greenland is already becoming less salty and less dense, and so less able to sink. The sinking of denser ocean water is a key driver of circulation. “The slowing of ocean circulation will profoundly alter the ocean overturning of heat, fresh water, oxygen, carbon, and nutrients, with impacts felt throughout the global ocean for centuries to come,” concludes the study’s lead author.
Salon reports further that altered major currents in the Southern Ocean will impact phytoplankton production around the world because these currents carry vital nutrients to far-ranging locations. The study’s authors indicate that sometime between 2050 and 2100 the impacts on surface productivity will become apparent. While there is uncertainty in these conclusions because of the complexity of the processes being modeled, this is another example of how ecological linkages between the atmosphere and oceans can drive global change in ways that could be very damaging to civilization.
The Washington Post notes the conclusion of a recent study that the Eurasian ice sheet retreated at a rate of 2,000 feet per day at the end of the last ice age. This conclusion is based on studying the patterns left by the edge of the ice sheet that are found in the ocean sediments off of Norway. This is the fastest rate of retreat ever documented, and has implications for how quickly ice in Greenland and Antarctica could melt and raise global sea levels in today’s warming world. This rate of retreat was temporary but demonstrates that, under certain conditions, ice sheets can disintegrate much faster than we’ve ever witnessed.
And to top off “this week in melting ice,” The Washington Post reports on a recent study of the Petermann Glacier in Greenland, which concludes that the glacier is melting faster than previously thought. In particular, the glacier is raising and lowering with the tides, and this “has carved a large cavern at the base of the glacier and allowed warm water to regularly stretch beneath it. As the glacier lifts and migrates, the water can rush in for over a mile, thinning the ice by as much as 250 feet a year in some places.” This mechanism for melting is not included in current models and, if widespread, could result in quicker glacial retreat and faster sea level rise.
In southern California, coastal erosion from storm activity has resulted in the collapse of a hillside supporting ocean-view homes in San Clemente. The Guardian reports that residents are barred from inhabiting the unsafe structures, and it is not clear when or if they will be able to return. As an alternative to such emergency declarations, many advocate for “managed retreat,” but Grist describes the complexities of applying this concept to the California coast. Wealthy homeowners want to armor the coast to protect their properties rather than move, but such projects have long been opposed by the California Coastal Commission. The cost of buying out expensive coastal properties as part of a planned retreat is enormous, as is the liability of not allowing armoring and then having properties damaged or destroyed. And then there’s the question, “managed retreat to where?”
The Inflation Reduction Act contains a strong incentive (one of its many “carrots”) to create clean hydrogen gas, which is likely to be an important source of power for heavy industry as it moves away from fossil fuels. An op-ed in the New York Times notes that key provisions of implementing regulations will determine what qualifies as “clean” hydrogen, and how easy it will be for poorly-crafted rules to stimulate the production of hydrogen using fossil fuels. A Volts podcast describes how updates after 30 years to two policy documents issued by the Office of Information and Regulatory Affairs could have far reaching effects on how the cost and benefits of proposed federal regulations are determined (note: a nerdy but important topic!). The Hill notes that these changes will bring more focus on long-term benefits and costs.
The drought emergency in the Colorado River basin has almost reached a breaking point. The ex-Secretary of the Interior, Bruce Babbitt, argues in a New York Times op-ed that the Department of Interior must take the lead to help states dependent upon the river’s water reach an agreement to reduce allocations. If the issue ends up in court, it could take years to resolve, by which time the flow of the Colorado may drop so low that it will no longer be able to flow past the dams (“deadpool”). The Interior Department has suggested that cuts be shared equally among California, Nevada and Arizona, which differs from the “last in, first out” principle previously enshrined in legal agreements that would force most cuts on Arizona and Nevada.
The California Water Blog has an excellent summary of the problem, noting that “Water use in the lower Colorado River basin is 70-80% for irrigated agriculture, with about four-fifths of this supporting feed crops for livestock. Agricultural water use’s share of the economy is about 4%, and some fallowing historically has been a buffer for dry times. Urban water use is about 20-30% of Colorado River basin water use, but supports over 90% of the economy and people.” Grist also has an excellent video summary of the problem. The Washington Post visits California’s Imperial Valley, where the agricultural industry uses more Colorado River water than the states of Utah, Wyoming, Nevada and New Mexico combined. While the farmers can see the “writing on the wall,” particularly as some of their water is used to grow alfalfa that is exported as cattle feed, they plan to fight for their water rights.
Nicholas Kristof notes in the New York Times that “the West was built on cheap water that is now running out from underpricing and overuse just as climate change is amplifying droughts.” He visits the Rio Verde Foothills, outside of Scottsdale, Arizona, where the need to truck in water is generating household water bills the size of mortgages.
Marjorie Taylor Greene recently posted on Twitter that “If you believe that today’s ‘climate change’ is caused by too much carbon, you have been fooled.” Salon reports that she explained why, which involves our planet’s rotation, the gravitational pull of other planets and our galaxy’s rotation as it travels through the universe (and no, I’m not making this up). Greene has over 705,000 followers on Twitter. The Guardian describes how, since Elon Musk purchased Twitter, the level of abuse targeted at climate scientists has skyrocketed, with some scientists who have been trying to provide accurate information disengaging to protect their mental health.
However, climate scientist Michael Mann observes in The Guardian that the once-powerful climate-denial movement has become an irrelevant sideshow in Australia, as the massive wildfires that caused their “black summer” have brought climate action into mainstream politics. An op-ed in the Washington Post examines the misinformation being used to fight expansion of offshore-wind power in the United States. Bloomberg reports that even Fox News spends less time questioning the reality and causes of climate change — now they just promote doubts about its severity and the need to take action.
Inside Climate News describes a legal battle at the heart of how we rebuild and expand our electrical grid to handle the transition from fossil fuels. “The debate comes down to a question of whether local utilities should automatically be the ones to build and own transmission lines in their territories, or should they be forced to compete in a bidding process with a variety of other companies that want to build and own the lines.” The debate has generated interesting coalitions on each side of the issue, with the Koch-funded Americans for Prosperity joining environmental groups in opposing making utilities the only transmission provider.
Anthropocene Magazine reports on the latest research in the field of agrivoltaics, where solar panels and crops are co-located on the same land. “We already know that agrivoltaics can increase land-use efficiency, produce plenty of electricity on minimal land, and may also improve crop yields by shielding plants from heat and wind.” The new research points out that installing panels at a specific height above crops can reduce panel temperatures by up to 10 °C, compared to traditional panels constructed over bare ground. At lower temperatures, solar panels are more efficient converting sunlight into electricity. Another article notes research suggesting that the shade provided by solar panels offers excellent conditions for growing biocrusts, the complex communities of cyanobacteria, algae, lichens and mosses that form a thin layer at the surface of dryland soils. These crusts fertilize the soil and protect it from eroding or blowing away as dust. Growing biocrusts is of interest for restoring degraded drylands.