California's strict limits on diesel air pollution appear to have paid off. Since the limits were added in 1990, diesel exhaust-related deaths have been halved, with the largest reductions in deaths seen in lower-income communities, a new study finds. "Everybody benefits from cleaner air, but we see time and again that it's predominantly lower-income communities of color that are living and working in close proximity to sources of air pollution, like freight yards, highways and ports. When you target these sources, it's the highly exposed communities that stand to benefit most," said study author Dr. Megan Schwarzman, a physician and environmental health scientist at the University of California, Berkeley's School of Public Health. For more on this, see our press release at Berkeley News.

California's electricity prices are among the highest in the country, new research says, and those costs are falling disproportionately on a customer base that's already struggling to pay their bills. PG&E customers pay about 80% more per kilowatt-hour than the national average, according to a study by the energy institute at UC Berkeley's Haas Business School with the nonprofit think tank Next 10. "California's retail prices are out of line with utilities across the country," said UC Berkeley assistant professor and study co-author Meredith Fowlie, citing Hawaii and some New England states among the outliers with even higher rates. "And they're increasing."

Climate-induced sea-level rise, along with natural and human-induced subsidence is causing coastal communities to experience sea-level rise four times faster than the global average. In a study published in 2018, Manoochehr Shirzaei at Arizona State University and Roland Bürgmann at the University of California, Berkeley show that major portions of San Francisco Bay's shoreline are sinking faster than the sea is rising. For more on this, see our press release at Berkeley News.

California's electricity prices are growing so high that they threaten the state's ability to convince enough people to ditch fossil fuel-powered cars and appliances, new research says. The state's electric rates are now two to three times what it costs to provide power, a paper released by the energy institute at UC Berkeley's Haas School of Business and the nonprofit think tank Next 10 reported. Severin Borenstein, a UC Berkeley energy economist who spearheaded the paper, said he's concerned that California is saddling its electric rates with too many things that are divorced from the direct cost of powering homes and businesses. The state could end up in a situation where electric rates are "vastly higher than the true cost of using electricity," Borenstein said. "At the same time, we're going to have rates that are going to be so high that it will be a huge discouragement to using electricity for things that we need people to adopt if we're going to decarbonize the economy."

President Joe Biden and his administration want to recalibrate the "social cost of carbon," a metric used to inform public policy decision making by putting a price on the non-market impacts of carbon emissions on the environment and human health. In a new paper, a group of researchers in the fields of economics, ethics and environmental science offered a series of recommendations for the revision process. "Economic analysis is at the heart of the regulatory process in the U.S. and will therefore play a major role in shaping and informing the ambitious climate goals from the new administration," said David Anthoff, study co-author and assistant professor of energy and resources at the University of California, Berkeley. "Our recommendations offer a roadmap for how this can be done in a way that is both scientifically rigorous and transparent."

A new study published this week in the journal Nature shows that while human-controlled freshwater sources make up a minimal portion of the world's ponds, lakes, and rivers, they are responsible more than half of all changes to the Earth's water system. Using NASA's ICESat-2 satellite, researchers monitored more than 227,000 bodies of freshwater–ranging in size from the Great Lakes to tiny ponds over period spanning roughly a year and a half. Researchers found that 57% of global seasonal water storage variability occurs in human-controlled reservoirs. "This large proportion is even more striking when one considers that reservoirs only account for 3.9% of the 227,386 lakes analyzed in this study," said UC Berkeley professor Sarah Cooley, the study's lead author. "While the water cycle is generally portrayed as a natural process, our finding that humans are responsible for the majority of seasonal surface water storage variability shows that we are now a key regulator of the water cycle."

In the struggle to survive the ever hotter deserts of California, there are winners and losers.

A global team of scientists, including UC Berkeley professor of energy and resources John Harte state in a recent study that without immediate and drastic intervention, humans face a "ghastly future" — including declining health, climate devastation, tens of millions of environmental migrants and more pandemics — in the next several decades. The researchers cite more than 150 scientific studies and conclude, "That we are already on the path of a sixth major extinction is now scientifically undeniable." "Humanity is running an ecological Ponzi scheme in which society robs nature and future generations to pay for short-term economic enhancement today," said Paul Ehrlich, a Stanford University professor emeritus of population studies and a co-author of the study.

Air pollution killed more Indians last year than any other risk factor, and Delhi is among the most polluted cities in the country. But the burden is unequally shared. Children from poor families in Delhi spend more of their lives outdoors. Their families are more likely to use wood-burning stoves, which create soot. They can't afford the air filters that have become ubiquitous in middle-class homes. And often, they don't even think much about air pollution, because they face more pressing threats, like running out of food. Joshua Apte, a pollution scientist at the University of California, Berkeley, helped with The New York Times study's research design, showing that pollution can shave years off a child's life.

The Bay Area's popular commuter corridors are also generators of carbon dioxide and micro pollutants. So what happened when COVID-19 forced most commuters off the road and into their homes? "...We saw this incredible change. The amount of CO2 released into the atmosphere in the Bay Area was 25% lower in that period than just before the lockdown six weeks before," says UC Berkeley professor Ron Cohen. "So we've been thinking about this as a model for the electric car." For more on this, see our press release at Berkeley News. A story on this topic also appeared in Science Daily.

As wildfires get bigger, more frequent and more dangerous, experts predict there will be no easing off unless the state and federal government spend billions of dollars on forest management, a reversal of decades-long policies of forest preservation. Listen as UC Berkeley professor of fire science, Scott Stephens joins other experts in talking about how to reduce fires in the coming years.

The best available science suggests that before Europeans arrived in California, wildfires claimed from 4.4 to 12 million acres annually. Native Americans knew to regularly burn their environment. "On reflection, anthropogenic burning is higher than what we had for the lower estimate," said the lead author of that paper, Scott Stevens of UC Berkeley. "You talk to Native American elders and they say they burned oak woodlands every 2-3 years."

As if the pandemic and economic recession weren't bad enough, millions of Californians now face recurring threats of abrupt blackouts during a heat wave in the nation's most populous state. UC Berkeley professors Daniel Kammen and Severin Borenstein discuss the state's problems with managing and storing power, and the complications of climate change and the pandemic.

Regenerative ranching - a holistic approach to managing grazing lands - may enhance ranchers' adaptive capacity and socioeconomic well-being while also providing an opportunity to mitigate climate change, according to a new study from Oregon State University, co-authored by Susan Charnley of the U.S. Forest Service and Paige Stanley of the University of California, Berkeley. Regenerative ranching practices rebuild ecological processes, allowing ranchers to reduce reliance on products such as chemical herbicides, pesticides and fertilizers, which are significant sources of greenhouse gas emissions.

Matteo Garbeletto, a University of California Cooperative Extension forest pathology specialist based at UC Berkeley, has developed a tool to tell if a tree is healthy. He named the app "Evalutree," and hopes the app will help PG&E track and trim, or remove, unhealthy trees. Some of California's largest wildfires in recent history have been caused when trees or branches fell on power lines.

Today, 40% of America's electricity comes from carbon-free sources. The Democratic presidential candidate has made getting that to 100% by 2035 a centerpiece of his $2 trillion plan to address climate change and create jobs. Getting there would take an enormous expansion of solar and wind capacity in the U.S., backed by mass adoption of energy-storage technologies and hanging onto existing hydroelectric and nuclear plants. A recent study from the Goldman School of Public Policy at the University of California, Berkeley determined that the U.S. grid could use existing technologies - solar, wind, nuclear, hydroelectric dams, and batteries - to supply 90% of its electricity needs by 2035. For more on this, see our press release at the Goldman School of Public Policy.

UC Berkeley researchers say they have found a better way to make natural gas power plants emit less carbon dioxide, a tool they hope can help fight climate change even while California tries to shift to renewable energy. Working with ExxonMobil, the Berkeley researchers identified a new technique that they say can catch about 90% of the planet-warming carbon dioxide emitted from a gas-burning plant and is six times more effective than the method currently used. For more on this, see our press release at Berkeley News.

Doomsayers and hopemongers alike may need to revise their climate predictions after a study that almost rules out the most optimistic forecasts for global heating while downplaying the likelihood of worst-case scenarios. The international team of scientists involved in the research say they have narrowed the range of probable climate outcomes, which reduces the uncertainty that has long plagued public debate about this field. "It is moderately good news. It reduces the likelihood of some of the catastrophically high estimates. If we were planning for the worst, the worst has become less likely," said one of the authors, Zeke Hausfather, of the Energy and Resources Group at University of California Berkeley. "But fundamentally, it means we must do more to limit climate change. We are not anywhere near on track to do that."

While overall power sales and wholesale electricity prices have fallen, and disconnections and late fees have been blocked to help vulnerable customers, experts consider utility companies to carry less risk in the face of the pandemic compared to other industries. Rapidly transitioning to a clean electricity grid can save customers money and create hundreds of thousands of jobs. A recent report from the University of California, Berkeley and GridLab found a 90% clean electricity grid is possible by 2035. For more on this, see the press release at The Goldman School of Public Policy. A story on this topic also appeared in The New York Times.

The U.S. can deliver 90% of its electricity from carbon-free sources by 2035, according to a new report from the University of California, Berkeley, and experts say accelerating clean energy deployments could also play an important role in the country's economic recovery. The falling costs of solar, wind and battery storage makes a 90% carbon-free grid feasible.

Because tropical forests absorb so much carbon dioxide, they're one of the best antidotes to climate change, but there's a catch. Heat stress and drought kill trees, releasing their stored carbon back into the atmosphere. A new study suggests that if warming reaches 2°C above preindustrial levels, vast portions of tropical forests will begin to lose more carbon than they take in. However, associate energy and resources professor Lara Kueppers is concerned that the study might be too optimistic in forecasting that cooler forests, especially in Asia and Africa, will continue to absorb large amounts of carbon as they warm. She says it's not certain that those forests will behave the way ones in South America have, or that they can adapt to the speed of human-induced climate change. "I don't have confidence that forests are going to be able to adjust on the time scale they will need to," she says.

A new study by associate agricultural and resource economics professor Joseph Shapiro finds that tariffs and other global trade barriers are lower for carbon-intensive products than greener ones, and that creates an "implicit subsidy to CO2 emissions" that amounts to $550 billion to $800 billion a year. This makes it harder to fight climate change, Professor Shapiro says. "The resulting change in global CO2 emissions has similar magnitude to the estimated effects of some of the world's largest actual or proposed climate change policies," he writes in the report. For more on this, see our press release at Berkeley News.

Tariffs and other features of the global trade system are interfering with climate goals and indirectly subsidizing fossil fuels, according to a new study by associate agricultural and resource economics professor Joseph Shapiro. He calls the interference an "environmental bias." He says it hasn't been measured in the trade system previously, but it's worth between $550 billion and $800 billion a year, amounting to more than direct subsidies that governments paid in the form of tax incentives to big greenhouse gas emitters in 2007. "This research is pointing out that different sets of policies that seem completely separate -- trade policy and climate change -- are connected quite closely in ways people might not have noticed," he says. For more on this, see our press release at Berkeley News.

A new report by Berkeley's Urban Displacement Project and the nonprofit EcoAdapt calls for climate change mitigation efforts to be integrated with other priorities, such as affordable housing, food and water security, and public safety, in order to prevent the displacement of disadvantaged individuals and families from their neighborhoods or communities. "Displacement -- whether temporary or permanent, forced or voluntary -- is an issue rooted in inequity and exacerbated by climate change," according to the report. "Climate change poses significant threats to the physical, cultural, spiritual, social, and economic displacement of communities around the world. It is also causing increasing mental and emotional distress or 'solastalgia' -- the loss of sense of place or identity."

If I could wave my magic wand and we all had electric cars tomorrow, I think this is what the air would look like, says chemistry and earth and planetary sciences professor Ron Cohen, an air quality researcher, referring to the beneficial side-effect of improved air quality during the COVID-19 shutdown. He and his team are monitoring air quality, and through an analysis of satellite measurements they've found a 32% decline in levels of nitrogen dioxide pollution over the first three weeks of shelter-in-place rules in Southern California, compared to the prior three weeks. They also, however, found a 26% reduction between the same periods in 2019, suggesting that spring weather contributed to the effect. "Driving is dramatically lower," he says, "but differences in weather between this year and last still make it hard to put numbers on how much cleaner the air is because of the shelter-in-place." Expressing dismay about how the pandemic is helping his research, he says: "It's terrible to get that view by people getting sick. ... It's not at all how we would design the experiment if we had a choice."

Asked in an interview about what global drops in air pollution due to the COVID-19 coronavirus pandemic can tell us, energy and public policy professor Dan Kammen, chair of Berkeley's Energy and Resources Group, says: "Well, it shows how quickly we can change our system. We've seen 30% to 40% drops in pollution over many of the world's cities. And it also shows us how quickly we could switch to clean energy if we took climate change as seriously as coronavirus. ... But it also shows us that actions do matter. Our individual decisions, whether we take an extra trip, whether we just drive to go get one thing at the store and come back, those actions all add up. And we scale it up to industry and to countries and regions. It really shows us that if we put our mind to it and if we invested in science we could not only do a far better job on climate change but we could also do it in a much more equitable way than we're doing now." Warning that overconsumption and its attendant pollution resurged after 9/11, and the same thing could happen when the coronavirus threat subsides, he says we'll be battling climate change for decades. "And so the real question is can we learn the positive lessons out of this horrible experience with coronavirus and say we want to switch to clean energy now? It's cheaper in many places and we want to invest in better systems so that low-income communities can actually generate their own power. Make themselves more resilient. And we're not doing that with coronavirus today by denying some of the poorest communities testing and respirators. And we're doing the same thing on climate. So we're making a natural disaster into a social disaster when we have all the tools to make this into a chance to really build a green stimulus." Link to video.