On The Two Year Anniversary Of The Deepwater Horizon Oil Spill In The Gulf Of Mexico, It's Worth Putting

Brad Plumer in the Washington Post explains a new study on the dramatic drop in carbon emissions in the U.S. over the past five years. This graph shows a hypothetical level of emissions that were projected based on trends from 1990-2005, compared to the actual level of emissions in 2012. It then breaks down the causes.

Plumer explains:

The recession and financial crisis, obviously, made a big difference. A weaker economy has meant less demand for energy — that was responsible for more than half the drop compared with business as usual.

Meanwhile, Houser and Mohan find the U.S. economy actually hasn’t become vastly less energy-intensive over time (the blue bar). Yes, overall efficiency has gone up — Americans are buying more fuel-efficient cars and trucks, etc. But the country is also no longer shedding manufacturing jobs as quickly as it was during the 1990s. So the amount of energy we use per unit of GDP has generally followed historical trends, improving only gradually.

The real change has come in the type of energy that the United States is using. The country is now relying more heavily cleaner forms of energy than it used to, and that explains about half of the fall in emissions

Forest cover on Borneo over time, projected to 2020. Deforestation, driven mostly by clearing land to produce palm oil plantations, means less habitat for species such as orangutans, and more carbon emissions from disturbed peat lands.

The species groups that are proportionally most in danger (the proportion of species within that grouping that are imperiled) are overwhelmingly freshwater species. Freshwater mussels, crayfishes, stoneflies (stonefly larvae live in freshwater), freshwater fishes and amphibians are the most at risk. This demonstrates the substantial need for a focus on conservation of freshwater habitats.

The sex of a sea turtle hatching is determined by temperature. Nests incubated at cooler temperatures produce more males, while nests incubated at warmer temperatures produce more females.

This could be a problem with climate change. As global temperatures rise, nests will be incubated at higher temperatures, producing fewer males. As this study found, climate change could lead to turtle nests with few to no males, skewing sex ratios and endangering the persistence of sea turtle populations. As the authors note:

“[O]nce incubation temperatures are 35°C, there are almost no more males produced (1 per 50 000 eggs laid)... As turtles return to the rough neighbourhood of their natal breeding grounds, it seems likely that for populations already producing more than 80% females, there will be a real extinction risk if they continue to nest at the same time of year and conditions warm by a few degrees.” 

But the bigger issue may be the increasing number of unviable eggs with rising temperatures. As the authors claim:

“[T]he primary concern in scenarios of climate change and rising incubation temperatures [is]... the high hatchling mortality in excessively warm nests...While climate warming still poses a threat to sea turtles, it is not the skewed sex ratios per se that will threaten population survival but rather higher mortality within clutches.”

Harvard political scientist Theda Skocpcol analyzed the failure of the 2009 Cap & Trade bill to determine what caused climate legislation to fail while health care reform succeeded. In her report, she claims that a major failure was that the environmental coalition focused on gaining republican support (which was reasonable, as Republicans had previously supported cap and trade, including 2008 Republican Presidential nominee John McCain), without recognizing that the environment had become a politically polarized issue, with Republicans turning against environmental legislation.

In an interview with The Washington Post's Brad Plumer, she states:

One of the things that really surprised me in my research came from pulling together scores from the [League of Conservation Voters]. And you see a clear pull on politicians from grassroots conservative opinion around 2006 and 2007. Climate-change denial had been an elite industry for a long time, but it finally penetrated down to conservative Republican identified voters around this time. That created new pressures on Republican officeholders and candidates. And I don’t think most people noticed that at the time. Even John McCain. I have this figure that shows him moving up on LCV scores for most of the last decade [i.e., casting more pro-environmental votes] and then pulling back suddenly to the lowest level starting in 2007.

In a report Tuesday, Environment and Climate Change Canada said the 51 separate herds [of boreal caribou] across the country remain under pressure from human and natural disturbances to their habitat more than five years after the federal and provincial governments concluded a protection agreement.

The range of the boreal caribou extends across the country from Yukon to Labrador, but its forest habitat has been increasingly disturbed by industrial activity such as forestry, mining and oil and gas development, as well as by forest fires, the spread of pests and other impacts of climate change.

This graph shows net forest conversion (deforestation that replaces forest with a new land use) from 1990-2010. Brazil and Indonesia stand out as the hot spots of deforestation.

In contrast, China, the United States and Vietnam experienced afforestation and reforestation.  

Avg. daily precipitation in the U.S. over the course of a year

Source: MetricMaps

A recent report from the Energy Information Administration found that U.S. plant owners and operators are getting ready to retire 27 gigawatts’ worth of coal generation, or about 8.5 percent of the coal fleet, between now and 2016. Considering the substantial contribution of burning coal to climate change, coal plant retirements are one of the greatest ways to reduce carbon emissions.