President Barack Obama, left, and Brazil's President Dilma Rousseff, front row third from right, applaud as they pose with world leaders for a group photo at the COP21, United Nations Climate Change Conference, in Le Bourget, outside Paris, today.

World leaders meet in Paris for climate talks

The U.N.-organized gathering of 151 heads of state and government comes at a somber time for France.

about 1 hour ago

 France's President Francois Hollande, right, shakes hand with Canadian Prime Minister Justin Trudeau.

Pledges, protests greet Paris climate talks

Microsoft founder Bill Gates, President Barack Obama and French President Francois Hollande will launch a joint initiative today.

about 14 hours ago

 French President Francois Hollande, holds a news conference after the Climate Change special session held during CHOGM (Commonwealth heads of Government meeting) in Malta on Friday.

Hollande, activists gear up for climate conference

President Barack Obama, the leaders of China, Russia and more than 140 other countries will converge on Paris to launch high-stakes talks.

1 day ago

Board questions EPA draft report on fracking

The draft report by the independent Science Advisory Board notes inconsistencies in an EPA study of fracking’s impact on water supplies.

2 days ago

 French Prime Minister Manuel Valls, left, and French President Francois Hollande talk to each other as they arrive for a group photo at the France-Oceania summit on the sideline of the Climate Change conference, which starts this week.

Despite terror alert, France gears up for climate talks

Two weeks after the attacks in Paris, France faces a big security challenge, a global mega-conference on climate change.

3 days ago

As temperatures rise, glaciers melting faster

Grinnell Glacier is disappearing due to decades of warming temperatures and may not exist as early as 2030.

3 days ago

 An Indian man rests in front of an air cooler in May to cool himself on a hot summer day in Hyderabad, in the southern Indian state of Telangana.

U.N. agency: 2015 is hottest year on record

The agency’s chief, Michel Jarraud, said it is likely that the world has now warmed by 1 degree Celsius over pre-industrial times.

4 days ago

Saint Vincent College launches green initiatives

Water bottle refilling stations, elimination of styrofoam containers are among the measures.

5 days ago

 Arletta Scott Williams, Alcosan's executive director, says "we need to extend the schedule. We need to change the parameters. And while we’re going through all of this, that’s when we start to get the outcry for green infrastructure. Which was something we had looked at early on. … Nobody was buying in, so we dropped back to the approach we took.”

Alcosan supports greener overflow solutions

Spokeswoman says 2026 deadline impossible, especially as it tries to satisfy greener, not “grayer” approach.

5 days ago

El Nino could be the most powerful on record, scientists say

A key location of the Pacific Ocean is now hotter than recorded in at least 25 years.

1 week ago

An Alcosan plan to treat sewage overflows

The solution features massive underground tunnels to store water until the treatment plant can process it.

1 week ago

 The Ohio Stadium along the Olentangy River in Columbus.

How a sick river got healthy

The once-foul Olentangy, bisecting Ohio State's campus, has become a “living laboratory” through group efforts.

1 week ago

 Migrating monarchs

Earthweek: Diary of a changing world

Events in the world’s climate for the week ending Friday, Nov. 20.

1 week ago

 Arletta Scott Williams, executive director of Alcosan, announces details of the $2 billion plan to address sewer overflows.

Alcosan plans miles of tunnels to transport wastewater

The sanitary authority is under pressure from federal regulators to reduce sewage overflows during heavy rain.

1 week ago

Regulators reviewing Shenango Coke Works' compliance with 2012 consent decree

Federal and county authorities planning greater scrutiny for ongoing smokestack emissions at Neville Island plant.

1 week ago

Pittsburgh officials point finger at 'bureaucrats in Washington' for sewage storage plans

City officials and other environmentalists want to see the plan focus on natural, green components first.

1 week ago

U.S., Cuba sign first environmental accord since thaw

The United States and Cuba signed an agreement Wednesday to join forces and protect the vast array of fish and corals they share.

1 week ago

EPA plans to reduce air pollution drifting across state lines

EPA proposes new rule to significantly reduce the downwind drift of smog-forming power plant pollution from one state to others.

1 week ago

 Allen Freeman of Detroit, who is a member of Michigan United, walks Thursday along Liberty Avenue, Downtown, where citizens gathered outside the William S. Moorhead Federal Building to support the EPA’s Clean Power Plan.

Pittsburgh hearing underway on EPA's new carbon emissions rules

During the first of two days of public comment, federal regulators heard mostly from clean energy advocates on why they support the rule.

2 weeks ago

 King Salman of Saudi Arabia waits to receive leaders Tuesday at a summit of Arab and South American leaders in Riyadh, Saudi Arabia. The Saudis submitted a climate pledge Tuesday.

Saudi Arabia presents climate pledge ahead of Paris summit

The Saudi pledge was symbolically important because the desert kingdom has been seen as reluctant to join the fight against global warming.

2 weeks ago

This year could be 1 degree C above 19th-century average

To measure global warming, scientists compare today’s temperature level with that of the latter part of the 19th century.

2 weeks ago

Drought drives bears into Calif. town in search of food

Tourists hoping to see a bear in Sequoia National Park this fall probably stand a better chance of spotting one in a tiny California town.

2 weeks ago

 Maureen Copeland plants at University Square in Oakland as part of StormWorks, a project of Nine Mile Run Watershed Association.

‘Green Team’ finds storm overflow solutions

PWSA’s Green Team helps inspire green infrastructure across the city.

3 weeks ago

 President Barack Obama, flanked by Vice President Joe Biden, left, and Secretary of State John Kerry, announces his decision to reject the Keystone XL pipeline proposal, at the White House.

Obama administration nixes Keystone XL pipeline

The decision caps a seven-year saga that became one of the biggest environmental flashpoints of Barack Obama’s presidency.

3 weeks ago

Republican U.S. presidential hopefuls bash Keystone rejection

Republicans seeking the White House in the November 2016 presidential election quickly voiced their disagreement.

3 weeks ago

 In January 2014, the Board of Health, at the urging of director Dr. Karen Hacker, agreed to seek accreditation with the Public Health Accreditation Board,

Gas drilling prompts fight against health department accreditation

The group Protect Our Parks says the Allegheny County Health Department hasn’t done enough to stop gas drilling around county property.

3 weeks ago

McKeesport votes to join intergovernmental land bank

Mayor Michael Cherepko says it will help the city deal with its vacant properties.

3 weeks ago

Allegheny County Health Department will fly air pollution flags

Allegheny County’s flag program aims to educate students and communities about air pollution.

4 weeks ago