Killer heat fueled by climate change could cause an additional 150,000 deaths this century in the biggest U.S. cities if no steps are taken to curb carbon emissions and improve emergency services, according to a new report.

The three cities with the highest projected heat death tolls are Louisville, with an estimated 19,000 heat-related fatalities by 2099; Detroit, with 17,900, and Cleveland, with 16,600, the Natural Resources Defense Council found in its analysis of peer-reviewed data, released on Wednesday.

California on Wednesday released an updated draft of its cap-and-trade regulations that for the first time includes language that would link its carbon market to a similar scheme in the Canadian province of Quebec.

The draft language called for the mutual acceptance of compliance instruments like allowances and offset credits between the two jurisdictions.

It also called for a common allowance registry and auction, and included provisions for tracking allowances which are designed to enhance market security.

A newly found fungal disease has been linked to a steady decline of landscape and avocado trees in suburban Southern California neighborhoods, says a newly released University of California-Riverside study. Besides a decline of avocado trees in the Los Angeles area, researchers from the Plant Pathology department at University of California-Riverside also have linked this new fungus to the branch dieback of trees.

California energy regulators will hold a workshop on May 9 for private solar power company BrightSource Energy's proposed 500-megawatt Hidden Hills solar power plant in California estimated to cost more than $2.7 billion.

According to releases late Thursday by the California Energy Commission and BrightSource, the project, if approved, will provide power to PG&E Corp under two purchase agreements already approved by state's utility regulators in 2010.

Energy technology: Better ways of storing energy are needed if electricity systems are to become cleaner and more efficient. Summer in Texas last year was the hottest on record. Demand for power spiked as air conditioners hummed across the state. The Electric Reliability Council of Texas (ERCOT), the state grid operator, only narrowly avoided having to impose rolling blackouts. To do so, it had to buy all the electricity it could find on the spot market, in some cases paying an eye-watering 30 times the normal price.

California orange and lemon growers are bracing for a deadly bacterial disease that could ravage the state's $2 billion citrus industry after the first infected tree in the state was identified in a suburban Los Angeles yard.

The tree ailment, called Huanglongbing, citrus greening or yellow dragon disease, is usually spread by the Asian citrus psyllid, a tiny, aphid-like winged insect that feeds on the leaves of citrus trees.

Climate change will make conserving the world’s biodiversity — including the human benefits associated with conservation, such as clean air and water — much more challenging and expensive, research reveals.

Sustainable Brands Conference 2012

According to a group of international researchers convened by Conservation International, climate change may in some cases drive up costs by more than 100%.

Electric vehicles in general are a great step in reducing emissions that cause global warming. The emissions from a gasoline-powered car are always greater than the emissions created to charge an electric vehicle. However, a new analysis by the Union of Concerned Scientists (UCS) suggests that the "greenness" of electric vehicles is not uniform across the country. They break down the country into regions that are good, better, and best for electric vehicles. Note there is no "bad" region in the country because electric vehicles outperform gasoline vehicles everywhere.

About 3.7 million Americans live within a few feet of high tide and risk being hit by more frequent coastal flooding in coming decades because of the sea level rise caused by global warming, according to new research.

If the pace of the rise accelerates as much as expected, researchers found, coastal flooding at levels that were once exceedingly rare could become an every-few-years occurrence by the middle of this century.

Coca-Cola Co. and PepsiCo Inc. are changing the way they make the caramel coloring used in their sodas as a result of a California law that mandates drinks containing a certain level of carcinogens bear a cancer warning label. The companies said the changes will be expanded nationally to streamline their manufacturing processes. The changes have already been made for drinks sold in California. Coca-Cola and PepsiCo account for almost 90 percent of the soda market, according to industry tracker Beverage Digest. A representative for Dr Pepper Snapple Group Inc.