February 15 2019

February 15 2019

last five years are the hottest on record, understanding sea level rise in the Eemian, aridification strikes the Colorado River and PG&E, Trump gets a Twitter lecture from teenagers

The New York Times reports on NASA’s announcement this week that 2018 was the 4th hottest year on record. Similar findings were released independently by NOAA and Berkeley Earth, all noting that the 18 warmest years on record have occurred in the past 19 years, and the five hottest years have been the last five. The clear message; global warming is not a future problem… it is here now. An op-ed in the Sacramento Bee encourages Governor Newsom to recognize climate change as a public health emergency.

Those seeking to downplay the problems associated with climate change have often cited greenhouse studies that conclude plants grow faster with more CO2 in the atmosphere, suggesting that plant growth will help mitigate the impact of carbon dioxide emissions. Of course, a greenhouse does not reflect actual conditions in the environment, and a new analysis summarized by the New York Times concludes that as the world warms plants (and soil) will absorb less carbon dioxide. This is mainly due to the impact of higher temperatures and drier conditions.

Stefan Rahmstorf of the Potsdam Institute reviews recent evidence about the impact of climate change on the Atlantic Meridional Overturning Circulation (AMOC). A slowing of the AMOC, or “the Gulf Stream,” would have major impacts on the climate of the northern hemisphere. He concludes that recent reviews by the IPCC and the U.S. Climate Assessment regarding the slowing of the AMOC are overly conservative. He argues that the empirical evidence matches climate model projections of slowing, and there are no other explanations for what we’ve observed to date (a remarkable cooling of the north Atlantic).

The last time the earth was as warm as now was in the Eemian period (115,000 years ago). A problem that has been puzzling paleoclimatologists for a long time is that while temperatures were similar to today, during the Eemian sea levels were 20-30 feet higher. This suggests strongly that the warming we have created will cause a relatively fast rise in sea level, and scientists have been debating how ice sheet collapse might be the mechanism that will cause this rise to occur. The Washington Post has a great article about this issue.

The Washington Post looks at the promise and problems with “advanced” nuclear power, such as the designs being promoted by Bill Gates’ company, TerraPower. It is going to be hard for us to meet our climate goals without nuclear power but, as the article demonstrates, there are still many technical problems to be addressed before “advanced” designs are commercially feasible.

The Guardian reports on a new study that concludes loss of ice in the Hindu Kush and the Himalayas during this century will have drastic impacts on water availability for over 1.65 billion people. Even if we successfully limit global temperature rise to 1.5°C over pre-industrial levels, something that will be very difficult to achieve, 36% of the ice in this region will be lost. If we do not control emissions, the projected ice loss rises to two-thirds, altering river flows (and agricultural productivity) in countries from Pakistan to China.

The recent Worldwide Threat Assessment released by U.S. intelligence agencies calls climate change a national security threat, posing risks to global stability due to competition for resources, economic distress and associated social discontent. InsideClimate News reports on these and related findings delivered to Congress, which were overshadowed in the news by a Presidential tweet (an unfortunate media obsession) calling our senior intelligence officials “naive.”

Yale e360 has the third installment in its excellent series on the drought in the Colorado River basin and its implications for water in the west (while drought implies a short-term state, it is important to note that what we might be seeing is the long-term drying [or “aridification”] of the basin). The basin is near the point where “junior” water rights holders will have to relinquish their water to holders of “senior” water rights, which happened last year on the Yampa, a Colorado tributary. The Nature Conservancy and others are working with the agricultural community to reduce water demand in order to protect riverine ecosystems while supporting sustainable agricultural production.

InsideClimate News has an excellent summary of the role of climate change in the drying of the Colorado River basin, and reports that the affected states just met a U.S. Bureau of Reclamation January 31 deadline to adopt voluntary water conservation plans. An article in the Los Angeles Times provides more detail on the challenging multi-state negotiations underway regarding the management and allocation of the waters of Lake Mead, the largest reservoir on the Colorado.

The Brookings Institution’s recent analysis of projected climate impacts across the country points out the irony that in much of the country Republicans are voting for people who are opposed to climate policy, even though these voters are very vulnerable to climate impacts. This is particularly true in the South, and suggests that as climate impacts become more extreme a broader coalition to support climate action might emerge. As evidence of this, an article in the Atlantic describes how the Republican governors of Florida, Idaho and Arizona are taking action about the future of water in their states, which is in essence climate change adaptation. Of course, they are not yet talking about climate change, which means they are treating the symptom without addressing the cause, but at least this is movement in the right direction.

The Washington Post reports that PG&E did too little, too late to address the increased risk to their operations from wildfires due to climate change. The Post notes many other corporations are underestimating their risk (by up to two orders of magnitude!), and an op-ed in the New York Times notes that until climate risk is properly priced in our market economy we will continue to use the wrong economic signals when making investments for the future. Michael Bloomberg makes a similar argument in the Los Angeles Times.

Meanwhile, the New York Times reports that Townsville, Australia, is the latest community to deal with massive flooding caused by an intense downpour (in seven days the community received the equal of its total annual average rainfall). This flooding brought an unusual hazard; crocodiles and snakes in the streets. However, the greatest damage may have been in the interior of Queensland, where a heartbreaking article in the Guardian describes the devastation of ranches, livestock herds and wildlife by floods of astonishing magnitude.

President Trump’s recent tweet wondering what happened to “global waming [sic])” during the outbreak of the polar vortex was a painful and infuriating display of ignorance and dissembling, particularly since the last four years were the hottest years since reliable measurements of atmospheric temperature began in the 19th Century. I therefore found this headline from Esquire particularly cathartic, and enjoyed seeing the President get lectured by teenagers on the difference between weather and climate.

Meanwhile, Bill Maher notes that climate change is the real national emergency, and InsideClimate News reports on the introduction by Congresswoman Ocasio-Cortez of a resolution in the House of Representatives “recognizing the duty of the federal government to create a Green New Deal.”