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This Week in Climate Science: Green Psychology, Public Health, and Biofuels

By David Kroodsma

Credit: istockphoto

Welcome to Climate Central’s weekly climate science roundup. This roundup summarizes noteworthy climate science studies published in the previous week, with a special emphasis on work that might not have been covered by major media outlets.

This week in climate science:

  • The psychology of being green.
  • Massachusetts’s residents want modest action on climate change.
  • Powering the U.S. on algae biofuels will require much land and water.
  • Biofuel crops in Brazil cool the landscape.
  • Climate change expands habitat for tiger mosquitoes.
  • The rapid growth of China’s greenhouse gas pollution.
  • Organic solar cells show promise.
  • An editorial: governments must pay for clean-energy innovation.

 

Feature: It isn't easy being green
Journal: Nature Climate Change
Author: Chris Woodside
 

Credit: istockphoto

The Gist: People are motivated to be more environmentally-responsible largely by social pressures.

Summary: This article summarizes research on why people decide to use energy more efficiently. According to a few studies, global energy use could be cut by 16 to 20 percent by 2020 at little cost through a number of efficiency measures. However, adopting these measures often requires consumers to make a choice, such as choosing a more efficient appliance or vehicle. This article looks at why consumers decide to buy greener products, finding that status is often more important than economics. That is, people buy green products to be seen as buying green products.
 
This article also describes a study in which researchers asked people their opinions on a “low carbon” lifestyle and then the researchers analyzed the people’s body language as they responded. The researchers found that the majority of individuals who said that they valued being green had body language that suggested otherwise. The researchers believe that most people were lying to themselves — they didn’t actually value being green.
 
Publication: The 80 Percent Challenge: A Survey of Climate Change Opinion and Action in Massachusetts
By MassINC Polling
Authors: Steve Koczela, Benjamin Forman, and Caroline Koch
Credit: istockphoto
The Gist: A majority of Massachusetts residents believe climate change is happening and want modest action to address it.

Summary: Three years ago, the Massachusetts legislature passed the 2008 Global Warming Solutions Act, which committed the state to reduce greenhouse gas emissions by 80 percent by the year 2050. How popular is this measure with Massachusetts’ residents?

This report, prepared by MassINC polling, finds that a large majority (77 percent) of state residents believe climate change is happening and at least partially due to human activities (59 percent), although only one third of residents said climate change was a high priority in the long term.

Nonetheless, most residents said they would be willing to pay more for renewable energy: 60 percent would pay $5 dollars more a month on their electricity bill for cleaner energy, and just under half would pay 10 cents more per gallon for gasoline if the revenue was invested in roads and public transit.

Perhaps most interestingly, though, few respondents knew about the state’s efforts to address climate change. Only 14 percent of respondents had heard about the 2008 legislation.


Paper Title: National microalgae biofuel production potential and resource demand
Journal: Water Resources Research
Authors: Mark S. Wigmosta, André M. Coleman, Richard J. Skaggs, Michael H. Huesemann, and Leonard J. Lane.
The Gist: Using current technology, algae can be cultivated to produce biofuels. Almost half of U.S. petroleum use could be offset, but huge amounts of land and water would be necessary.

Summary: This study analyzes the best locations in the United States for algae cultivation for biofuels. They find that the U.S. could produce 220 billion liters of oil per year, which is roughly half of the country’s annual consumption. But to produce this much fuel, 5.5 percent of the land would have to be used for algae, and the total amount of water needed would equal three times what is currently used to irrigate all crops in the country. The algae would be much more water efficient if only the best locations were used, which the authors found to be along the Gulf Coast, the southeastern coastline, and the Great Lakes. By using only these locations, algae biofuel could still offset about one fifth of the nation’s oil.


Paper Title: Direct impacts on local climate of sugar-cane expansion in Brazil
Journal: Nature Climate Change
Authors: Scott R. Loarie, David B. Lobell, Gregory P. Asner, Qiaozhen Mu and Christopher B. Field.

 

Sugarcane farming in Brazil. Credit: istockphoto
The Gist: Sugarcane crops in Brazil’s Cerrado, when compared to other crops or pastureland, cool the local climate because they cause more evaporation.

Summary: When natural vegetation is replaced by pasture or cropland, it alters the climate. Natural vegetation stores more carbon than agricultural vegetation, so converting the land to agriculture releases carbon dioxide (CO2) to the atmosphere, which in turn warms the global climate. At a local level, the climate can be changed in two ways. If the crops are darker or brighter than the ecosystem they replaced, they will absorb or reflect more sunlight, affecting local temperatures.
 
Also, the amount of evaporation that transpires through plants' leaves is different for different types of crops and natural ecosystems. Just as sweat cools one’s skin, plants that induce more evaporation cool local temperatures.

In this study, Loarie and his colleagues find that pastureland and agriculture, mostly because of reduced evaporation, warm the Brazil’s Cerrado, which is the main agricultural belt in the country. However, sugarcane, because it causes relatively more evaporation, has a much smaller local warming effect than other crops.
 
In recent years, sugarcane has expanded rapidly across the Cerrado, replacing other crops and pasture. The sugarcane is planted to produce ethanol, which in theory reduces the country’s greenhouse gas emissions and cools the planet. Because of increased evaporation, the crop also slightly cooled the landscape.
 
The authors admit that it is difficult to compare this local effect with the global effects from greenhouse gas emissions associated with the crops.


Paper Title: Climatic Factors Driving Invasion of the Tiger Mosquito (Aedes albopictus) into New Areas of Trentino, Northern Italy
Journal: PLoS One
Authors: David Roiz, Markus Neteler, Cristina Castellani, Daniele Arnoldi, Annapaola Rizzoli.
The Gist: The ranges of disease-carrying mosquitoes may shift as the climate changes, and this paper models, in detail, how one such mosquito’s range may change in Italy.

Summary: Over the past 30 years, the Asian tiger mosquito (Aedes albopictus), native to southeast Asia, has been introduced to all continents except Antarctica. The mosquito can carry numerous diseases, including dengue fever, Chikungunya, and West Nile virus, meaning it may increase risks to human health. The tiger mosquito cannot survive in cold climates, and it will likely see its range increase with global warming. This study analyzes the mosquito’s habitat in northern Italy, characterizing the climates where it can survive. The authors then use climate models to predict the mosquito’s range in 2050. They find it may expand its habitat, and they suggest applying their methodology to predict its range for the rest of Europe.


Paper Title: From carbonization to decarbonization? Past trends and future scenarios for China’s CO2 emissions
Journal: Energy Policy
Authors: Jan Christoph Stecke, Michael Jakob, Robert Marschinski, Gunnar Luderer.
The Gist: The authors analyze the growth in China’s CO2 emissions, and project future emissions.

Summary: As an economy grows, its energy use as a percentage of its Gross Domestic Product (GDP) decreases. For instance, although the United States uses more energy than Mexico, it spends a smaller percentage of its total economy on energy than Mexico does.
 
In China, although CO2 emissions have been growing, they have grown more slowly than the economy. In the past few years, however, because of an increased reliance on coal, which produces high amounts of CO2, the amount of CO2 produced has increased rapidly. The authors project future energy growth in China, showing that in order to meet the climate goals set by world leaders, China must dramatically cut the carbon intensity of its energy — that is, how much CO2 is emitted for every unit of energy the country produces.
 
The paper also provides a number of figures comparing China’s emissions to the rest of the world. In the past decade, the vast majority of the world’s increase in carbon emissions came from China.


News Article: Outlook Brightens for Plastic Solar Cells
Journal: Science
Author: Robert F. Service
The Gist: Solar panels made of cheap organic material may be just around the corner.

Summary: Solar panels today are made of silicon — which is expensive to produce — or materials such as tellurium, which may be in short supply. There is a major need to develop solar panels that are cheaper and made from more abundant materials.

Scientists have tried for many years to make solar panels from cheap organic materials, but their efforts have mostly come up short. Now, a scientist at Stanford University, Michael McGehee, reports that he has made an organic solar panel that is 9.2 percent efficient, which is at the lower range of commercially viable solar panels. Another few research centers are reporting efficiencies of 8 percent, and some expect to reach 10 to 15 percent in the next few years.

The next challenge is to make organic materials as durable as the metals used in normal solar panels. A solar cell needs to survive years in the sun, and most organic materials break down when exposed to UV light. The same scientists report that they are making significant strides in improving the durability of organic solar panels.


Editorial: Climate change, energy security, and risk — debating nuclear new build in Finland, France and the UK
Journal: Nature
Author: Marty Hoffert
The Gist: Governments must fund clean-energy innovation.

Summary: Dr. Hoffert has published several influential and highly-debated papers on the need for breakthrough technologies to solve climate change. In this editorial, he argues that governments — not the private sector — must spearhead investment in clean energy technologies. He points out that technologies such as the Internet were originally developed by the U.S. government. Another technology, the light water nuclear reactor — the basis for 85 percent of the world’s nuclear power plants — was originally developed by the U.S. Navy for nuclear submarines. The private sector, he argues, can’t take the financial risks that are necessary in order to develop expensive new technologies. Hoffert argues that the U.S. government must make a much larger investment.