Latest Posts by envirographs - Page 4

Oyster reefs are in rough shape over much of the world, threatened by over-harvesting in combination with pressures from exotic species (including disease) and pollution. This means those coastal areas are losing the valuable ecosystem services, such as water filtration and protection from storm surges, oyster reefs provide.

Source:

Beck, M. W., Brumbaugh, R. D., Airoldi, L., Carranza, A., Coen, L. D., Crawford,

C.,…Guo, X. (2011). Oyster reefs at risk and recommendations for conservation,

restoration, and management. BioScience, 61(2), 107-116. doi:http://dx.doi.org/10.1525/bio.2011.61.2.5

Historic drought in California affects more than California. Local impacts of climate change have broader implications.

Everglades (and south Florida, including Miami) with 5ft of sea level rise

Everglades (and south Florida, including Miami) with 4ft of sea level rise

Everglades (and south Florida, including Miami) with 2ft of sea level rise

The Florida Everglades, where elevation above sea level is often measured in single digits, is on of the most susceptible areas of the country to sea level rise. In addition to its low coastal elevation, the Everglades are threatened as a result of a history of wetland degradation that changed the way water flowed through the large wetland system. Restoring natural freshwater flows will help protect the everglades from the intrusion of salt water due to sea level rise, but it must be done quickly.

Dr. Harold Wanless of the University of Miami Department of Geological Sciences created a series of maps showing the Everglades under varying scenarios of sea level rise. This is the Everglades in 1995. 

While deforestation is a major source of global carbon emissions (see previous two posts), the expansion of agriculture into drained organic soils also releases carbon. Wetlands, and especially peatlands, have waterlogged soils. As a result, their soils are depleted of oxygen, preventing decomposition. This means that the carbon in plants and animals is stored in the soils. When these soils are drained, the oxygen returns and organic material decomposes. Decompostion releases the carbon stored in that material. Thus, draining wetland soils releases carbon dioxide and contributes to climate change.

FAO adds emissions from cropland expansion into drained organic soils to deforestation. The result: significant increases in carbon emissions from Indonesia, which has substantial peatlands.

The figures from the previous post on deforestation (from the UN Food and Agriculture Organization) have a significant impact on carbon emissions and climate change. Because deforestation releases carbon stored in plants and soils, deforestation has become a major source of global carbon dioxide emissions. Countries with greater deforestation have greater emissions as a result.

Forest conversion in Brazil 1990-2010 released 25.8 billion metric tons of CO2. The next four greatest emitters from deforestation were Indonesia, Nigeria, the Democratic Republic of the Congo and Venezuela. Combating climate change will require reigning in deforestation.

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.  

California's climate change law (AB 32), which puts a price on carbon emissions and creates a cap-and-trade system to reduce greenhouse gas emissions, is yielding substantial reductions in emissions from oil refineries. These refineries are a major source of carbon emissions, along with a host of other toxic chemicals like ammonia, lead, benzene, mercury and acid gases.

Data from the California Air Resources Board shows that 11 refineries substantially reduced emissions between 2010 and 2011, in addition to cuts in the release of other toxic pollutants. Evidence shows that these reductions not a result of cuts in production, but to refineries investing in and upgrading equipment in response to AB 32. An example is Valero’s refinery in Benicia, CA, which decreased covered emissions by over 95,000 metric tons, while also cutting ammonia emissions by 98%, sulfuric acid by 84%, and benzene by 49%, through the installation of a new flue gas scrubber.

(continued from previous post)

The big story in Houser and Mohan's study is where these cleaner forms of energy are coming from that are responsible for half of the drop in emissions. It's generally assumed that the drop is a result of cleaner and cheap natural gas pushing out dirty coal. However, Houser and Mohan show that we shouldn't be counting out reneables.

Plumer:

Natural gas is indeed pushing out dirtier coal, and that makes a sizable difference (burning natural gas for electricity emits about half the carbon-dioxide that burning coal does). But wind farms are also sprouting up across the country, thanks to government subsidies. What’s more, industrial sites are burning more biomass for heat and electricity, while biofuels like ethanol are nudging out oil. All of that has done a lot to cut emissions.

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

The Regional Greenhouse Gas Initiative (RGGI) is a cap and trade program involving nine northeastern states:  Connecticut, Delaware, Maine, Maryland, Massachusetts, New Hampshire, New York, Rhode Island and Vermont. New Jersey was a part of the program but Gov. Christie pulled the state out of the agreement in 2011. The purpose of the program is to lower emissions from power plants in the northeast. On its face, carbon emissions have declined from 188 million tons of carbon-dioxide in 2005 to 91 million tons in 2012. However, much of that is due to the recession and cheap natural gas replacing dirty coal. At present, power plants emit less carbon than the current cap. This gives little incentive for them to invest in energy efficiency and renewable energy.

In an effort to further drive investment in efficiency and renewables, the RGGI released a proposal to progressively lower the emissions cap through 2020. The 2020 cap will be 14% below the current level of emissions.

Brad Plumer of the Washington Posts notes that "Between now and 2020, the new RGGI scheme is hoping to cut annual emissions by about 13 million tons. That’s about 0.06 of all power plant emissions in the United States last year. A rounding error. Ultimately, RGGI might best be thought of less as a solution to climate change and more of a revenue-raiser for the Northeast. It’s also an experiment of sorts — a way for policymakers to figure out what works and what doesn’t in climate policy." 

Change in mean sea level over the past two decades. The lull in 2011 was the result of La Nina, not a pause in climate change.

This graph shows greenhouse gas emissions from major point sources (power plants, industrial boilers) by state. It becomes clear immediately that Texas is a major outlier, representing far greater emissions than any other state. Indiana, Pennsylvania, Ohio, Louisiana, Illinois and Florida are other states with large emissions.

The reduction in CO2 emissions from the energy sector in the U.S. over the past 5 years (see previous post) was due in large part to a reduction in emissions from coal. In 2009, the financial collapse led to diminished use of all fuel sources and greenhouse gas reductions across the board. Since then, the expanding use of natural gas has increased it's carbon footprint, but the decline in the use of coal and the subsequent decrease in greenhouse gas emissions associated with coal is remarkable. Coal is the most carbon-rich fossil fuel, so any declines from that source is good news for the climate.

Even as global carbon dioxide emissions hit a record high in 2012, CO2 emissions from energy generation in the United States fell to 1994 levels. This is a 13% decrease over the past 5 years. President Barack Obama has set a climate goal of lowering greenhouse gas emissions 17% from 2005 levels over the next decade. By the end of last year, levels were down 10.7% from the 2005 baseline, meaning America is more than halfway towards that goal.

The reductions come from a variety of places. It is, in part, because of new energy-saving technologies. In part because of a weakened economy. In part because of a growing share of renewables in the energy sector. And in part because cleaner natural gas is displacing carbon-rich coal.

While this is good news, there are some important caveats. 1.) This is only the U.S. Emissions are rising rapidly in other parts of the world. 2.) This is only CO2 emissions from energy production. This is a big source of greenhouse gas emissions, but not the only one. 3.) This rate of decline is probably not fast enough to avert the worst of climate change.

Land use change on Cape Cod. This image shows a dramatic increase in development on the Cape from the 1950s into the twenty-first century. This is problemmatic, as the increased development leads to loss of native habitats and an increase in water pollution. The latter is largely a result of the fact that very little development is connected to sewers, and nitrogen from septic systems quickly leaches through the sandy soils into ponds, streams and bays.

Further, development is threatened by climate change; specifically sea level rise and increased costal erosion .

A study of "fossil beaches", those areas where geology and fossils show they were once pre-historic coasts, is aiming to give us a better picture of the threat of sea level rise. Researchers acknowledge that, even during natural climatic shifts, carbon dioxide is the primary driver of global warming and cooling. During the Pliocene, carbon dioxide was at 400ppm and sea level was much higher. We are currently at 393ppm and rising. We are likely to cross over 400ppm in the next several years. Thus, looking at sea level rise during the Pliocene can give us a picture of what sea levels may look like as a result of current global warming. This map shows where the coastline was in the U.S. during the Pliocene.

According to the National Climatic Data Center, the average global temperature for 2012 made it the 10th warmest year on record since record keeping began in 1880. It also marked the 36th consecutive year with a global temperature above the 20th century average. The last below-average annual temperature was 1976.

The map shows 2012 temperatre anomalies, with red indicating higher than average temperatures and blue lower. Looking at the United States,2012 was the warmest year on record.

A recent study looked at the demographics of an elephant population in Samburu, Kenya, and the impact of poaching. This graph shows the annual PIKE, or Proportion of Illegally Killed Elephants. PIKE is calculated as the number of illegally killed (poached) elephant carcasses divided by the total number of elephant carcasses discovered that year. The graph shows a recent dramatic increase in poaching.

The authors state:

Illegal human killing caused over half the recorded mortality in the Samburu elephants over the age of 9 (and indirectly caused the deaths of all victim’s dependent calves under 2 years). The high illegal killing in the latter part of the study had serious ramifications for the structure and organization of the population... the illegal killing appeared to select adult individuals in Samburu and particularly males resulting in increasing skew in the sex ratio over the course of the fourteen year study. Social disruption also resulted, with numerous well known and stable family groups being completely lost (i.e. no surviving breeding females) causing increased numbers of unaffiliated juveniles (orphans)

According to the New York Times, the recent spike in poaching, the greatest in decades, is driven by rising demand for ivory in Asia.

Another graph from Theda Skocpol's analysis of why the 2009 Cap and Trade bill failed, this one looking at increasing political polarization between the Democrats and the GOP from the 1970s on.

*The LCV (League of Conservation Voters) average reflects LCV scores given to lawmwakers, which are based on their votes on important environmental legislation. The higher the score the more "pro-environment" the lawmaker.

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.

I'm back...

I apologize for my 5 months hiatus. I intend to divert my attention back to Envirographs, to continue using graphs and maps to explore environmental problems, trends and solutions.

The conservation status of turtles and tortoises, nearly 60% of which are threatened. Many critically endangered turtles are in Asia, such as the Yunnan Box Turtle, Yangtze Giant Softshell Turtle and Philippine Pond Turtle. The leatherback and hawksbill sea turtles are also critically endangered.

44% of crocodilians are threatened according to the IUCN. The Chinese alligator, Orinoco crocodile, Phillippines crocodile, Cuban crocodile, Siamese crocodile and Gharial are all considered critically endangered. A conservation success story, the American alligator, once facing extinction, is now considered "low risk", although the American crocodile is "vulnerable".

...and lizards, a quarter of which are threatened.

From reptiles, the conservation status of the world's snakes

Conservation status of reptiles, which include snakes, lizards, turtles & tortoises, tuataras and the crocodilians

The environmental blog Mongabay.com created a series of graphs from the IUCN Red List, which evaluates the conservation status of plant and animal species and lists those that are under threat. I'll be posting a series of them from different groups.

The first is the conservation status of herps, or reptiles and amphibians.