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Yale Environment 360

Yale Environment 360 is an online magazine offering opinion, analysis, reporting and debate on global environmental issues. We feature original articles by scientists, journalists, environmentalists, academics, policy makers, and business people, as well as multimedia content and a daily digest of major environmental news. Yale Environment 360 is published by the Yale School of Forestry & Environmental Studies and Yale University. We are funded in part by the Gordon and Betty Moore Foundation and by the John D. and Catherine T. MacArthur Foundation. The opinions and views expressed in Yale Environment 360 are those of the authors and not of the Yale School of Forestry & Environmental Studies or of Yale University.

Renewable Energy

Inexpensive Solar Cell Makes Hydrogen From Sunlight

written by Yale Environment 360

Researchers have developed a device that can store solar energy by inexpensively converting it to hydrogen — an important step toward making solar power available around the clock.

The technology, which which was recently described in the journal Science, is a type of “water splitter,” a device that can efficiently divide water into its constituent parts: hydrogen and oxygen.

The concept is important for solar energy storage because hydrogen gas can be used directly as fuel and is relatively easy to store, the researchers say. The device can convert 12.3 percent of the energy in sunlight to hydrogen, according to the report; conventional solar cells, in comparison, convert roughly 16 percent of energy from sunlight to electricity, but a significant portion of that energy is lost when converting it to a form that is easily stored.

The design of this water splitter is an improvement over previous iterations, the researchers explain, because it is made from inexpensive materials — nickel, iron, and perovskite, an abundant mineral that has recently been found to improve solar cell efficiency. They say the device’s longevity and reliability will need to improve, however, before it becomes a practical, large-scale solar energy storage option.

09/30/2014 0 comment

Renewable Energy

World’s Largest Coal Company Plan’s Billion Dollar Solar Plant in India

written by Yale Environment 360

Continuing its push to increase investment in renewable energy, India’s energy ministry is working with the state-controlled coal mining company Coal India Limited — the largest coal mining operation in the world — to install solar power projects worth $1.2 billion.

The company is in the process of selecting sites for solar plants, which are expected to have a combined total energy-generating capacity of 1,000 megawatts, the Times of India reports. India currently has roughly 2,200 megawatts of grid-connected solar power capacity, so Coal India Limited’s contribution would be a substantial increase.

When prime minister Narendra Modi took office earlier this year, he pledged to bring electricity to the homes of the nation’s entire population of 1.2 billion — 400 million of whom lack any access to electricity — within the next five years, largely through solar installations.

09/26/2014 0 comment

Renewable Energy

Planet Set to Reach CO2 Threshold in 30 Years, Researchers Say

written by Yale Environment 360

Only 1.2 trillion metric tons of carbon dioxide can be emitted in the future if nations are to avoid causing the global mean surface temperature to rise more than 2 degrees C beyond the pre-industrial average, according to researchers with the Global Carbon Project.

Historical (black dots) and projected (red dots) global CO2 emissions in trillions of metric tons. (Image credit: Friedlingstein et al., Nature Geoscience 2014)

Combined historical and future carbon dioxide emissions must remain below 3.2 trillion metric tons to have a 66-percent chance of keeping that temperature increase below 2 degrees C — the internationally accepted benchmark for restraining global warming. But two-thirds of this allotment has already been emitted, and at the current pace of emissions, the global population will burn through the rest within the next 30 years, the researchers conclude.

CO2 emissions rose 2.3 percent in 2013 and are on track to increase by another 2.5 percent in 2014, according to the report, which was released ahead of tomorrow’s UN climate summit in New York. China and the U.S. were the leading emitters in 2013 and were responsible for 28 percent and 14 percent, respectively, of global CO2 emissions.

09/24/2014 1 comment

Renewable Energy

Trees Growing Significantly Faster in Warming Climate, Study Finds

written by Yale Environment 360

An analysis of data spanning 140 years from one of the world’s oldest forest study sites indicates that trees have been growing significantly faster and stands have become larger since the 1960s.

The study, published in Nature Communications, was based on 600,000 individual tree surveys conducted since 1870 at a central European forest study site. European beech and Norway spruce, the dominant tree species in the experimental plots, grew 77 and 32 percent faster, respectively, than they did 50 years ago, the analysis found.

The study also found that stands of trees increased in volume by 30 percent for beech and 10 percent for spruce trees. The trends are primarily due to rising temperatures and longer growing seasons, the researchers say, although increasing carbon dioxide and nitrogen levels in the atmosphere could also play a role.

The stages of tree development haven’t changed, the researchers say; instead, trees are moving through their development trajectory much faster than before. The changes could affect other plants and animals in the forest ecosystem that rely on specific phases of forest development. Those species may need to become more mobile to survive, the study says.

09/22/2014 2 comments

Clean Transportation

Shift to Mass Transit Could Have Major Economic and Climate Benefits

written by Yale Environment 360

Expanding public transportation and infrastructure that promotes walking and biking throughout the world’s cities could save $100 trillion and cut transportation-related carbon emissions by 40 percent by 2050, according to an analysis by researchers at the University of California, Davis, and the Institute for Transportation and Development Policy.

Urban transportation accounted for roughly one-quarter of all transportation-related emissions in 2010, the report said, and these emissions could double by 2050 as growth continues in major cities in China, India, and other developing countries.

This chart compares projected urban transportation-related emissions in 2050 under two scenarios: “business as usual,” shown in red, and the “high shift” scenario, shown in green. Under the “high shift” scenario, countries make major improvements in urban mass transit and infrastructure that promotes walking and biking. Transportation-related emissions from 2010, in black, are shown for comparison. (Image source: UC-Davis, ITDP)

If China alone were to develop extensive bus rapid transit and commuter transit networks, its predicted transportation-related emissions in 2050 could be cut by 40 percent, the analysis found.

The U.S. — currently the world’s largest contributor to urban transportation-related emissions — is seeing declines in that sector as population growth slows, vehicle fuel efficiency improves, and people drive less. But those emissions cuts could accelerate sharply, to half the levels currently predicted for 2050, if urban mass transit were improved.

Redirecting funds from road construction, parking garages, and other infrastructure elements that encourage car ownership to public transportation would save trillions in public and private dollars, the analysis found.

09/19/2014 4 comments

Renewable Energy

Tackling Climate Change Could Pay Off in as Little as 15 Years, Report Finds

written by Yale Environment 360

Limiting greenhouse gas emissions globally over the next 15 years is both economically feasible and likely to save money, according to a new report from the Global Commission on the Economy and Climate. Between 2015 and 2030, nations are expected to invest roughly $90 trillion in urban, land-use and energy infrastructure, the analysis estimated.

Steering those investments toward renewable energy, efficiency improvements, and other low-emission technologies would make that global investment more costly, the panel of government and business leaders conceded — but only marginally, adding about $4 trillion overall. But these costs could eventually be offset by the lowered operating costs associated with renewable power, the report suggested.

Although they are difficult to quantify, health care savings associated with improved air quality would also offset costs. According to the report, the biggest challenges for governments will be enacting stronger rules and economic policies that favor low-carbon development, such as cutting the $600 billion that countries currently spend on fossil fuel subsidies.

The report highlights the plunging costs of renewable energy — solar technology costs have been cut in half since 2010, for example — and argues that limiting urban sprawl and deforestation are essential steps in combating climate change.

09/17/2014 1 comment

Renewable Energy

New High Resolution Maps Show Greenhouse Gas Emissions at City-Level

written by Yale Environment 360

Researchers have developed a new method for mapping global carbon emissions for individual cities on an hourly basis — a major improvement over previous techniques, which quantified greenhouse emissions less accurately and at coarser scales, according to researchers at Arizona State University.

The maps are derived from worldwide databases of population, power plants, and national fuel use statistics, and they encompass 15 years of data. Among other findings, the analysis revealed increased emissions in China, India, Europe, and the northern U.S. in 2010, after the peak of the global financial crisis.

Annual fossil fuel emissions for two years on either side of the global financial crisis. The top map is the year 2006; bottom map is 2010. Red and orange indicate above average emissions, and green indicates below average emissions. (Map credit: Gurney lab, ASU)

The researchers say this reflects faster recoveries from the crisis in those regions compared to, for example, the southeastern U.S., where emissions lagged in 2010.

The results of the analysis match ground-level emissions measurements, confirming the accuracy of the maps, the researchers say. They hope the research can be used to help craft — and enforce — future emissions policies.

09/15/2014 1 comment

Renewable Energy

U.S. Renewable Energy Growth in 2014 Dwarfs Fossil Fuel Plant Additions

written by Yale Environment 360

The U.S. this year has significantly scaled back coal and natural gas power plant additions compared to 2013, and solar and wind power capacity is far outpacing the 2013 installation rate, according to the U.S. Energy Information Administration.

No utility-scale coal plants were added in the first six months of 2014, whereas more than 1,500 megawatts of coal-fired power capacity had been added during the same period last year. Natural gas additions were cut roughly in half compared to the first half of 2013, while wind additions more than doubled and solar power increased by 70 percent.

The only coal plants scheduled to come online in 2014 are the Kemper plant in Mississippi, which will capture its own carbon emissions, and a small conventional steam coal plant in North Dakota, reflecting the challenging market for coal due to impending federal environmental regulations and competition from natural gas.

09/11/2014 0 comment

Renewable Energy

Smog in India Damaged Enough Crops to Feed 94 Million, Study Says

written by Yale Environment 360

Ground-level ozone, the main component of smog, damaged 6.7 million tons of Indian crops worth an estimated $1.3 billion in a single year, according to a new study published in Geophysical Research Letters.

That’s enough wheat, rice and other staple crops to feed 94 million people — roughly one-third of the country’s impoverished population. Arising from a combination of vehicle emissions, cooking stoves, and industrial sources, plant-damaging ozone has left many of India’s fast-developing cities among the most polluted in the world, according to the country’s Air Monitoring Center.

The number of vehicles there has nearly tripled in the past 10 years, rising from 50 million in 2003 to 130 million in 2013, and the country currently has no air quality standards to protect crops from ozone pollution. The researchers say the findings should be used to guide new ozone emission standards for the country.

09/10/2014 0 comment

Energy Efficiency

Buying Video Games on Disc is More Energy Efficient Than Downloading

written by Yale Environment 360

Downloading video games from the Internet creates a larger carbon footprint than driving to the store to purchase the same game on a Blu-ray disc, according to findings published in the Journal of Industrial Ecology.

For an 8.8-gigabyte PlayStation video game file — the average size of video games in 2010 — the resources required to produce, distribute, and dispose of Blu-ray discs are far less than the energy required to power servers, routers, and networks involved in downloading the game file, researchers say.

The advantages of discs decrease as file sizes shrink, the analysis found, and for game files less than 1.3 gigabytes, downloading has a smaller carbon footprint than purchasing the game on Blu-ray.

Between 2010 and 2013, however, game file sizes actually doubled for PlayStation4 and increased by 25 percent for PlayStation3. The analysis illustrates why it is not always true that digital distribution of media will have lower carbon emissions than distribution by physical means, especially when file sizes are large, the researchers say.

09/05/2014 0 comment

Water & Conservation

Six Strategies Could End Global Water Stress by 2050, Scientists Say

written by Yale Environment 360

Global water stress could be alleviated by the year 2050 if countries work to implement six key strategies ranging from building more reservoirs to controlling population growth, according to research from Canada and the Netherlands.

Water stress is defined as occurring when more than 40 percent of the water from a region’s rivers is unavailable because it is already being used — a situation that currently affects roughly one-third of the global population.

Writing in Nature Geoscience, the scientists propose six steps they believe can help reduce water stress: planting crops that use water and nutrients more efficiently; using more efficient irrigation methods; improving the efficiency of water use in homes, industry, and municipalities; limiting the rate of population growth so global population stays below 8.5 billion by 2050; increasing reservoir water storage capacity; and intensifying water desalination operations by 50-fold.

09/03/2014 1 comment

Renewable Energy

New Database Tracks Ecological Health Impacts of Dams on World’s Rivers

written by Yale Environment 360

A newly launched online database illustrates the impacts of nearly 6,000 dams on the world’s 50 major river basins, ranking their ecological health according to indicators of river fragmentation, water quality, and biodiversity.

The “State of the World’s Rivers” project was developed by the advocacy organization International Rivers and created using Google Earth. Users can compare the health of individual river basins, see the locations of existing and planned dams, and explore 10 of the most significant river basins in more depth.

For example, as this map of China’s Yangtze basin shows, at least 374 dams already exist in the basin, and at least another 167 are under construction or planned to be built. The ecological health of the region is showing signs of collapse, the database entry says: A 2014 study found that fish species in the Yangtze drastically decreased from 143 to 17 over the course of one year, due to overfishing and dam construction.

The 6,000 dams represented in the database are a small percentage of the more than 50,000 large dams that impact the world’s rivers, the organization notes.

09/02/2014 0 comment

Renewable Energy

Obama Seeks Climate Accord Without Congressional Approval

written by Yale Environment 360

The Obama administration is aiming to forge a legally binding, international agreement that would cut fossil fuel emissions and direct funds to poor nations dealing with climate change, without ratification from Congress, The New York Times reports.

The agreement would combine legally binding updates to an existing 1992 climate change treaty — allowing Obama to sidestep the constitutional requirement that treaties be ratified by two-thirds of the Senate — with voluntary pledges for specific emissions targets and aid to help poorer countries adapt to climate change. Nations would then be legally required to report progress toward their emissions targets at international meetings that would “name and shame” countries making slow or no progress, the Times reports.

Lawmakers from both political parties say that no climate agreement requiring congressional approval could be reached in the near future. Republican leaders are expected to oppose the agreement being worked on by the administration and say it would be an abuse of authority; leaders from poor nations are also expected to oppose the deal because they fear that wealthy countries will not abide by voluntary aid pledges.

A draft of a U.N. climate report to be released in November, leaked yesterday, stresses the urgency of international action to mitigate rising greenhouse gas emissions, according to the Times.

08/28/2014 1 comment

Renewable Energy

Health Care Savings Can Far Outweigh Costs of Carbon Cutting Policies

written by Yale Environment 360

Implementing policies to curb carbon emissions dramatically cuts health care costs associated with poor air quality — in some cases, by more than 10 times the cost of policy implementation, according to new research published in Nature Climate Change.

Policies aimed at reducing carbon emissions are as effective as laws targeting polluting compounds like ground-level ozone, also known as smog, and fine particulate matter, the MIT researchers say. An analysis of three climate policies — a clean-energy standard, a transportation policy, and a cap-and-trade program — found that savings from avoided health problems could recoup 26 percent of the cost of implementing a transportation policy, and up to to 10.5 times the cost of implementing a cap-and-trade program. A cap-and-trade program would cost roughly $14 billion to implement, whereas a transportation policy with rigid fuel-economy requirements could cost more than $1 trillion, according to the analysis.

Policies targeting specific sources of air pollution, such as power plants and vehicles emissions, did not lead to significantly larger benefits than cheaper policies, such as a cap-and-trade approach, the study found.

08/27/2014 1 comment

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