Business & Innovation
10 Sep 2014:
U.S. Renewable Energy Growth
In 2014 Dwarfs Fossil Fuel Plant Additions
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.
04 Sep 2014:
Buying Video Games on Disc Is
More Energy Efficient than Downloading
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
PlayStation game console and Blu-ray disc
. 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, the researchers say.
03 Sep 2014:
Mobile Phone Networks Can
Help Monitor Global Rainfall, Study Says
New research shows
that mobile phone networks, which cover 90 percent of the world's population, can help track rainfall events — a task that has proven difficult for both advanced satellite systems
and ground-level observation networks. By compiling data on signal disruptions from mobile phone networks in Burkina Faso in West Africa, a team of researchers was able to calculate with 95 percent accuracy both the location and volume of rain that fell, even during short-lived storms, according to a report in Geophysical Research Letters
. Mobile phone companies maintain detailed records on signal disruptions, which can occur when water droplets block and deflect signals between antennae, to determine whether their networks are functioning properly. By tapping into those records, researchers could distill data on rainfall events at extremely fine spatial and temporal scales. As mobile phone networks expand across the globe, such data could be used to create highly accurate rainfall maps, researchers say, although gaining access to records could prove difficult.
28 Aug 2014:
Rail Transport of U.S. Oil Up
By 9 Percent, Creating Rail Car Shortage
The amount of U.S. oil shipped by rail rose 9 percent during the first seven months of the year compared to 2013, reaching 16,000 carloads per week in July,
according to the U.S. Energy Information Administration
(EIA). U.S. crude oil production reached an estimated 8.5 million barrels per day in June for the first time in 18 years and is driving the increase in rail transport
, the EIA said. Only 3 percent of petroleum shipped by rail in 2009 was crude oil; now crude accounts for more than half. Over the past three years, much of the oil has come from the Bakken Shale, primarily in North Dakota. Between 60 and 70 percent of the more than 1 million barrels per day of oil produced in North Dakota has been transported by rail so far in 2014, according to the North Dakota Pipeline Authority. The demand for rail cars has created a backlog that's been particularly worrisome for farmers, who say their grain is rotting before shipping space is available
to take it to market.
20 Aug 2014:
Exporting Coal to Korea Could
Slash Emissions by 21 Percent, Analysis Says
Exporting U.S. coal to South Korean power plants could cut greenhouse gas emissions by 21 percent compared to burning it at less efficient U.S. plants, according to
researchers at Duke University
. The strategy could also generate more than $25 billion in economic activity in the U.S. and cut emissions of sulfur dioxide, nitrogen oxide, and particulate matter, the researchers say. For those benefits to occur, however, U.S. plants would need to replace the exported coal with natural gas, and South Korea must use the imported coal to replace dirtier sources of coal. South Korea's coal-fired power plants are newer and significantly more efficient than those in the U.S. — efficient enough to offset emissions associated with shipping the coal across the globe, the researchers say. However, they also caution that further studies are needed to assess the scenario's full environmental impacts, including water use, land use, and the degradation of vital habitats.
Interview: Drones Are Emerging
As Valuable Conservation Tool
Ecologist Lian Pin Koh
is co-founder of a project called ConservationDrones.org
, which is pioneering the use of
Lian Pin Koh
low-cost drones in conservation efforts and biological research across the globe. In an interview with Yale Environment 360
, Koh, a researcher at the University of Adelaide, explains how drones – also known as unmanned aerial vehicles (UAVs) – can help monitor protected areas, collect data in inaccessible regions, and even deter poachers. “In just the last couple of months,” he says, “there has been tremendous interest from universities and other research institutes that finally see the value in this technology.”
Read the interview.
View a gallery.
19 Aug 2014:
Wind Energy Prices at
All-Time Low, According to U.S. Report
The cost of wind power in the U.S. is at an all-time low of 2.5 cents per kilowatt hour, according to a new report
from the U.S. Department of Energy, and utility companies are in some cases electing to use wind as an energy source over fossil fuels because of its low cost. Although wind power grew modestly in 2013 — installations were only 8 percent of those seen in the record year of 2012 — it now meets 4.5 percent of U.S. energy needs, producing enough electricity to power 16 million homes. The country ranks second only to China in installed wind capacity, the report says, and wind power accounts for 33 percent of all new U.S. electric capacity additions since 2007. That progress has been heavily dependent on federal, state, and local incentives, however, and wind power's growth could slow if those incentives expire. Its viability could also fall if natural gas becomes more affordable than wind, the report cautions.
13 Aug 2014:
New Maps Show Flooding
Risks for Critical U.S. Energy Facilities
A new mapping tool
shows critical energy infrastructure in the U.S., such as power plants, refineries, and crude oil rail terminals, that may be vulnerable to coastal and
inland flooding, as well as areas that may be prone to flooding in the future. The maps, created by the U.S. Energy Information Administration and the Federal Emergency Management Agency, let users see which energy facilities could be in danger of flooding caused by hurricanes, flash floods, and other weather events, including street-level results for a particular address. The maps show areas that have a 1-in-100 (1 percent) and 1-in-500 (0.2 percent) chance of flooding annually, as well as areas that might be identified in the future as having a 1-percent annual flood hazard.
Green Innovations Are Bringing
Energy-Saving Technology Home
Advances in technology and consumer demand for energy-saving devices have made green technology
increasingly accessible. Many innovations are geared toward homeowners looking to lower not only their energy bills, but also the carbon footprints of their homes and daily activities. From solar-harvesting shingles and windows to shoe insoles that can power a smartphone, this Yale Environment 360
gallery explores a few of these energy-saving technologies.
View the gallery.
04 Aug 2014:
California Takes Steps to
Curb Lawn Watering During Severe Drought
In the midst of a severe, long-term drought, California is taking unprecedented steps to discourage watering of
A drought-resistant yard
residential lawns, with some areas offering residents substantial cash incentives for installing water-saving landscaping, AFP reports
. The "Cash in Your Lawn" program in Los Angeles offers residents up to $6,000 ($3 per square foot) for replacing their lawns with drought-tolerant plants, rocks, and pebbles. Throughout the state, Governor Jerry Brown recently prohibited lawn watering more than two times per week and banned fines for brown lawns, which homeowner associations sometimes impose with the intent of improving a neighborhood's appearance. The drought, currently in its third year, threatens the water supply of California's 38 million residents. Agricultural regions
have already seen severe water reductions, placing extra pressure on the state's groundwater reserves.
Interview: Making the Rights of
Farm Animals a Basic Green Issue
Conservation organizations have long sought to protect pandas, polar bears, and pelicans, but the welfare of
farm animals has largely been left to activist animal-welfare groups like the Humane Society of the United States
. For the past 10 years, that organization has been headed by the politically savvy Wayne Pacelle, who has greatly increased its visibility and influence. Under his leadership, the society has lobbied successfully to curb what it calls the worst excesses of “factory farms.” In an interview with Yale Environment 360
, Pacelle talked about how treatment of farm animals is linked to greenhouse gas emissions, why his group is promoting “meatless Mondays,” and why consumers should be willing to pay more for products from animals that are sustainably raised.
23 Jul 2014:
"Inglorious" Produce Campaign
Is Major Success for French Grocer
A major French grocery chain, Intermarche, has launched a novel campaign
to curb food waste
market visually flawed produce. The "Inglorious Fruits and Vegetables" campaign aims to revamp the image of imperfect and non-conforming produce, much of which is thrown away by growers because it doesn't meet grocery retailers' standards. Intermarche began welcoming the "Grotesque Apple," "Ridiculous Potato," "Hideous Orange," and other infamous items to its shelves, created posters to explain that the produce is as nutritious and flavorful as the more attractive versions, and reduced prices by 30 percent. The campaign was an "immediate success
," Intermarche says: Stores nationwide sold 1.2 million tons of "inglorious" fruits and vegetables in the first two days, and overall store traffic increased by 24 percent.
02 Jul 2014:
Roughly $80 Billion Wasted on
Power for Networked Devices, Report Says
The world’s 14 billion online electronic devices, such as modems, printers, game consoles, and cable boxes, waste around $80 billion in electricity annually because of inefficient technology, according to a new report
the International Energy Agency (IEA). In 2013, networked devices consumed around 616 terawatt hours (TWh) of electricity, with most of that used in standby mode. Roughly 400 TWh — equivalent to the combined annual electricity consumption of the United Kingdom and Norway — was wasted because of inefficient technology. The problem will worsen by 2020, the agency projects, with an estimated $120 billion wasted as devices such as refrigerators, washing machines, and thermostats become networked. Much of the problem boils down to inefficient “network standby,” or maintaining a network connection while in standby mode. Most network-enabled devices draw as much power in this mode as when fully active, the report notes. Using today's best technology could cut energy consumption by 65 percent, the IEA said.
26 Jun 2014:
Major U.S. Retailers to Limit
Pesticides That May Be Harmful to Bees
Home Depot and other U.S. retailers announced new policies to help limit the use of a group of pesticides suspected of contributing to widespread declines in bee
New warnings on plants aim to protect bees.
populations, Reuters reports
. Under the new rules, suppliers will be required to label any plants treated with neonicotinoid pesticides, or "neonics," that are sold in home and garden stores. Home Depot will require labeling by the fourth quarter of 2014, a company vice president said, and the retailer is testing to determine whether it's feasible to eliminate neonics altogether without compromising plant health. Another retailer, BJ's Wholesale Club, which has more than 200 East Coast locations, said it will ask suppliers to eliminate neonics by the end of the year, or label plants treated with them as requiring "caution around pollinators." An analysis of 800 peer-reviewed studies released this week by an international group of scientists found that neonics have been a key factor in bee declines
24 Jun 2014:
Concentrated Solar Power
Could Compete with Natural Gas, Study Says
Concentrated solar power (CSP) could meet a substantial percentage of current energy demand in some parts of the world, according to research
CSP plant in San Bernardino County, CA
published in the journal Nature Climate Change
. In the Mediterranean region, for example, the study shows that a grid-connected CSP network could provide 70 to 80 percent of current electricity demand, at no extra cost compared to natural gas-fired power plants. CSP could also feasibly meet energy demands in parts of southern Africa, according to researchers. CSP systems use mirrors or lenses to concentrate solar rays into a small area. The concentrated energy heats a liquid that produces steam to drive turbines, which means that the collected energy can be stored as heat and converted to electricity when needed — a major advantage over solar panels, which store energy much less efficiently.
12 Jun 2014:
U.S. Breweries Cut Water
Use Amid Widespread Drought Conditions
Major breweries in the U.S. are cutting back on the amount of water they use to brew beer as drought threatens their water supplies, the Associated Press
reports. MillerCoors, headquartered in Chicago, has reduced its water use by 9.2 percent since 2012, a company sustainability report said. Earlier this month St. Louis-based Anheuser-Busch, the largest U.S. brewer, reported that it has cut water use by 32 percent in the last five years. Employing strategies such as fueling boilers with wastewater, recycling water used to clean bottles and cans, and installing sensors to fine-tune irrigation in hop and barley fields, MillerCoors has cut water use to 3.48 barrels of water for each barrel of beer, the company says. The company is also giving $700,000 to landowners in the watershed of its Fort Worth brewery who make efforts to curb erosion and runoff by, for example, planting native grasses or rotating cattle grazing lands. Craft breweries typically use twice as much water as major breweries per barrel of beer, the AP notes, because they are smaller in scale and don't have access to the same technology.
11 Jun 2014:
Group Will Pay Farmers
To Create Temporary Migratory Bird Habitat
started by The Nature Conservancy aims to enlist California farmers in creating temporary habitats for migrating birds — a partnership that could become
more important as the state's long-term drought continues and the birds' wetland habitats dwindle. Using crowdsourced data, The Nature Conservancy (TNC) tracks the paths of migratory birds on their annual journey from Canada to South America to determine where and when the birds will need suitable wetland habitat for stop-overs in California's Central Valley. Then, in a sort of reverse auction, TNC asks farmers how much they would charge to temporarily flood their land to accommodate the birds, and pays farmers with the lowest bids to do so for a few weeks or months. The Nature Conservancy says the year-old program has been a success, enabling the organization to rent habitat for roughly 0.5 to 1.5 percent of what permanent protection costs. The program's budget is $1 million to $3 million annually. Forty farmers flooded roughly 10,000 acres last year, and sightings of key migratory bird species were 30 times above average, according to TNC.
Interview: The Small College That
Launched Fossil Fuel Divestment
When Stanford University announced in May that it would divest its endowment of coal mining companies, it was following the lead of a tiny college in rural Maine
that dubs itself “America’s environmental college.” A year and a half earlier, Stephen Mulkey, the president of Unity College
stood on a stage with Bill McKibben, the founder of 350.org and lead cheerleader for the divestment movement, to announce that his college would be the first institution of higher learning to rid its endowment of all fossil fuel holdings. In an interview with Yale Environment 360
, Mulkey, a climate scientist, talks about the ethical imperative behind the decision to divest, and his vision for, as he puts it, a re-engineering of the way the environmental sciences are taught.
05 Jun 2014:
Coating for Roof Tiles Could
Help Clear Smog-Causing Air Pollutants
Engineering students have created a roof tile coating
that, when applied to an average-sized residential roof,
Coated tiles (left) and an uncoated tile (right).
breaks down the same amount of smog-causing nitrogen oxides per year as a car driven 11,000 miles makes. If applied to one million roofs, the titanium-dioxide based coating, which costs roughly $5 per roof, could clear 21 tons of nitrogen oxides each day, the team calculated. That could put a noticeable dent in atmospheric levels of the pollutant; in Southern California, for example, an average of 500 tons of nitrogen oxides are emitted daily. The team, which was recently recognized in a U.S. Environmental Protection Agency student design contest, showed that their tiles could remove 88 to 97 percent of nitrogen oxides in laboratory tests — a feat that other roof tile prototypes have not demonstrated.
03 Jun 2014:
Developing Countries Lead
Global Surge in Renewable Energy Capacity
The number of developing nations with policies supporting renewable energy has surged more than six-fold in just eight years, from 15 developing countries
in 2005 to 95 early this year, according to a report from REN21
, an international nonprofit renewable energy policy network. Those 95 developing nations today make up the vast majority of the 144 countries with renewable energy support policies and targets in place. The report credits
such policies with driving global renewable energy capacity to a new record level last year — 1,560 gigawatts, up 8.3 percent from 2012. More than one-fifth — 22 percent — of the world's power production now comes from renewable sources. Overall, renewables accounted for more than 56 percent of net additions to global power capacity in 2013, the report says. Although financial and policy support declined in the U.S. and some European countries, China, the U.S., Brazil, Canada, and Germany remained the top nations for total installed renewable power. China's new renewable power capacity surpassed new fossil fuel and nuclear capacity for the first time, the analysis found.
02 Jun 2014:
New U.S. Coal Plant Rules
Could Lead to a Steep Drop in Emissions
The Obama administration today unveiled a sweeping new plan
that aims to cut carbon dioxide emissions from the nation’s 600 coal-fired power plants by roughly a third. Gina McCarthy, administrator of the U.S. Environmental Protection Agency, said the new rules would give states maximum flexibility
to achieve the goal of reducing power plant emissions 30 percent below 2005 levels by 2030. Hundreds of coal-fired power plants are expected to close under the EPA plan. But rather than immediately shutting down plants, states would be allowed to reduce emissions by making changes across their electricity systems — by installing new wind and solar generation or energy-efficiency technology, continuing to expand the use of natural gas, and by starting or joining state and regional “cap and trade” programs. “There is no one-size-fits-all solution ... so each state’s path can be different,” said McCarthy. The proposed regulations could be held up by legal challenges. Obama administration officials said the rules would lift the U.S. into a clear global leadership position
on combating global warming.
30 May 2014:
New Battery Technology
Could Offer Cheap Renewable Energy Storage
New battery technology that uses cheaper and safer materials to store large amounts of energy may soon enable utility companies to use more renewable power,
Iron-chromium flow battery technology
MIT Technology Review. The new device is a type of flow battery, and it uses liquid materials that rely on iron-chromium chemical reactions to store energy. California-based startup Enervault, developer of the new battery, figured out how to use materials that had been tried in batteries decades ago; Enervault overcame a key technical challenge that had caused the earlier batteries to quickly degrade. The new battery is large — it can store one megawatt-hour of electricity, or enough to run 10,000 100-watt light bulbs for an hour — and the materials last more than 20 years, according to its developer. Although the battery is inefficient compared to conventional batteries — it loses 30 percent of the energy used to charge it — it is still economically viable, the company says. The iron-chromium flow battery costs 80 percent less than vanadium flow batteries, a competing technology. The batteries are currently in use at a small power plant near Modesto, California.
29 May 2014:
Electric Airplane Debut
Offers Hopes for Cutting Emissions
The aircraft manufacturing giant Airbus recently unveiled
a fully-electric aircraft which, if widely adopted, could reduce the aerospace industry's carbon
The recently debuted, fully-electric E-Fan
dioxide emissions by an order of magnitude. The E-Fan aircraft has two, 30-kilowatt electric motors powered by a series of lithium-ion batteries in the wings of the plane, as well as a 6-kilowatt electric motor in the wheel to provide extra power during takeoff and taxiing. Despite incorporating highly energy-efficient and aerodynamic design elements, however, the E-Fan has only a one-hour range and cannot leave the vicinity of the airport. Airbus says that future designs will rely on electric-hybrid engine technology and that by 2050 such airplanes should be able to accommodate 70 to 80 passengers on a three-hour flight. The plans were spurred, in part, by the European Union's Flight Path 2050
, which aims to reduce the aviation sector's nitrous oxide emissions by 90 percent, noise pollution by 65 percent, and carbon dioxide emissions by 75 percent by 2050. "It's a very different way of flying," said Jean Botti, a technology officer at Airbus Group, "absolutely no noise, no emissions."
21 May 2014:
Trash-scooping Water Wheel
Cleans up Garbage From Baltimore Harbor
A new contraption
in a Baltimore river is helping to clear trash and debris — up to 50,000 pounds of it each day — from the city's Inner Harbor. The 50-foot-long
"water wheel" gathers garbage floating in the Jones Falls River, which runs through the city to the Baltimore Inner Harbor, and deposits it in a large dumpster so the trash can be hauled away. Two large booms funnel debris toward a conveyor belt powered by the wheel, which itself is powered primarily by the flowing river. When the flow isn't strong enough to turn the wheel, water pumps, run by solar panels lining a canopy over the wheel, turn on and push water up to spin the wheel. The water wheel was designed to handle the heavy debris and larger pieces of trash that the river often carries, said its designer, Baltimore-based Clearwater Mills. It began operating earlier this month and cost $750,000, with $500,000 of that contributed by the Maryland Port Administration, Co.Exist reports.
12 May 2014:
Global Renewable Energy Jobs
Grew by 14 Percent in 2013, Report Says
Renewable energy jobs grew by 14 percent to 6.5 million employees worldwide last year, led by the solar panel industry, according to a new report
from the International Renewable Energy Agency. Employing a
total of 2.6 million workers in renewable energy jobs, China led in hiring last year, followed by Brazil and the United States. The solar industry — spurred by increasing photovoltaic panel installations in Asia and falling prices — employed 2.27 million workers at the end of 2013, largely concentrated in China, the report said. The biofuel industry, with 1.45 million employees, and wind energy, with 830,000, were the second- and third-largest employers. Although policy changes in several countries have reduced wind energy installation jobs, operations and maintenance positions have experienced some growth, according to the report.
07 May 2014:
Stanford Drops Coal Stocks
From Its $18.7 Billion Endowment Portfolio
Stanford has become the first major U.S. university to divest its shares in coal-mining companies from its endowment funds, lending support to a growing nationwide movement calling for universities and
Fossil Free Stanford
pension funds to drop investments in fossil fuel companies. Citing guidelines that allow trustees to weigh whether “corporate policies or practices create substantial social injury” when choosing investments for the university's $18.7 billion endowment, the board decided, after five months of deliberation, to purge stakes in up to 100 companies worldwide that derive profits primarily from coal mining. A Stanford spokeswoman said that coal companies constitute a small fraction
of the university's total endowment investments, “but a small percentage is still a substantial amount of money." Board members said their decision was made partly because coal is the most carbon-intensive of any major fossil fuel and that less carbon-intensive energy sources are available.
29 Apr 2014:
Exxon Mobil Arctic Project
Possibly At Risk Over Russia Sanctions
Exxon Mobil's development of a Russian Arctic oil project valued at nearly $900 billion is at risk following recent U.S. sanctions on Russian officials as a result of Ukraine's ongoing political crisis, Bloomberg News reports
. Exxon Mobil has partnered with the Russian state-controlled oil company OAO Rosneft to drill an oil-rich geological structure known as Universitetskaya, which contains an estimated 9 billion barrels of oil, valued at $900 billion at current market prices. Rosneft's CEO, Igor Sechin, a longtime member of Russian President Vladimir Putin's inner circle, was sanctioned by the U.S. yesterday, exposing the partnership with Exxon Mobil to additional scrutiny. Exxon Mobil and Rosneft are set to invest an estimated $600 million in drilling at the site in the Kara Sea, which would make the project Exxon's most expensive to-date. A U.S. Treasury official said yesterday that U.S. companies can still do business with Rosneft, but some analysts say Russian companies could become wary of working with Western corporations in the future. Exxon said last week that the project is on schedule.
28 Apr 2014:
Economic Viability of Nuclear
Power Under Threat, Energy Group Says
Nuclear reactors in the U.S. need a boost — either through carbon taxes or regulations forcing coal-fired plants to slash emissions — or economic factors will force many to close, according to a report
from a non-profit group. Nuclear power — currently the only major zero-carbon, around-the-clock baseload power source — supplies 19 percent of U.S. electricity and is key to meeting President Obama's pledge to reduce emissions 17 percent below 2005 levels by 2020, according to the Center for Climate and Energy Solutions. The economic viability of the 100 nuclear reactors in the U.S. is worsening, the report says, because of the abundance of cheap natural gas and rising wind energy production. A carbon tax or some form of carbon trading — for instance, requiring coal-fired plants to purchase and blend their electricity output with nuclear power — will be essential to keeping nuclear plants from closing before the end of their lifespans, the report contends. Four power companies recently announced the early retirement of five nuclear reactors, which constitute more than 4 percent of U.S. nuclear capacity, the group says.
22 Apr 2014:
Run-of-River Hydropower Set
For Big Gains, Turbine Maker Predicts
A type of hydroelectric technology known as "run-of-river" hydropower is set to grow 10-fold over the next decade
, potentially becoming a $1.4 billion industry,
Hugh Keenleyside Dam
according to Dutch turbine maker Tocardo International BV. Run-of-river hydropower stations redirect part of a waterway through a diversion to spin turbines and generate electricity. Run-of-river is considered a more benign type of hydropower than large dam projects because it is a smaller-scale technology that doesn't create large upstream reservoirs that flood ecosystems and disrupt a river's natural flow. Some conservation groups are concerned
that problems with migratory fish passage and other environmental issues could outweigh the power-generating potential of run-of-river hydro projects. The company implemented its first project to harness tidal streams at Den Oever, Holland, and it has been operating for five years.
10 Apr 2014:
Mapping Program Helps
Cities See Money Saved by Planting Trees
New open-source software is helping cities better understand the benefits trees provide by calculating the value of the trees' ecosystem services, such as air quality improvements and CO2 storage. More than a dozen
cities have undertaken tree inventory initiatives, thanks to the OpenTreeMap software
, and residents have helped map more than 1.1 million trees worldwide. In addition to plotting a tree's location, users record its size, species, and other parameters that allow the software to calculate the tree's ecological value in terms of dollars saved through such benefits as cleaner air. San Diego's more than 340,000 mapped trees
, for example, are estimated to provide the city more than $7 million in benefits each year, including $4 million in air quality benefits and $2 million in reduced energy costs. In the coming months, the software will allow city managers to decide where to plant trees for maximum environmental benefit.