George H.W. Bush was the first president to sign the U.S. onto a global climate deal, a modest effort recognizing the threat of climate change, and possibly the last to successfully take on a wholesale revision of the Clean Air Act.

His administration at times pushed back against what it viewed as overly costly environmental regulations. But the 41st president—who cut his teeth in Texas’ oil industry—left what some admirers see as an impressive legacy of environmental laws.

They include the Clean Air Act Amendments of 1990, which used a then-cutting edge approach of emissions trading to cut air pollutants linked to acid rain; and the Global Change Research Act of 1990, which set up a climate change research program across 13 federal agencies and departments.

‘Conservation as a Core Conservative Value’

“We all know that human activities are changing the atmosphere in unexpected and in unprecedented ways,” Bush said in a February 1990 speech. Bush died Nov. 30 at age 94.

Bush’s legislative record also included signing the Oil Pollution Act of 1990, which set up a system for assigning liability for oil spills in the wake of the Exxon Valdez oil spill. He also campaigned in 1988 on a no-net-loss of wetlands platform, though many conservation groups said it fell short of the dramatic action needed to stem environmental damage from encroaching development.

Sen. Sheldon Whitehouse (D-R.I.), who has aggressively pushed for the U.S. to act on climate change, said Bush’s passing is only a further reminder of the political decline of environmentally minded Republican moderates, including Rhode Island’s own John Chafee, a senator who died in 1999.

“George H.W. Bush, like Rhode Island’s John Chafee, understood the Republican Party’s legacy of conservation as a core conservative value,” Whitehouse said in a statement to Bloomberg Environment. “Sadly, the rise of polluter funding now dominating the Republican Party has virtually erased environmental bipartisanship.”

For their part, Republicans paying tribute to Bush have stressed his military leadership during the end of the Cold War and first war in Iraq over his environmental achievements.

Clean Air Act

Bush oversaw changes to the nation’s air pollution law in 1990. It was the last time Congress came together in a bipartisan way to make any significant changes to the Clean Air Act, with the Senate ultimately approving the amendments on a 89-10 vote and the House following suit with a 401-25 vote.

The amendments created the first national cap-and-trade program, the Acid Rain Program, to reduce nitrogen oxides and sulfur dioxide pollution given off by power plants burning fossil fuels, notably coal.

In a cap-and-trade program, the sources of emissions subject to a pollution cap are required to hold allowances equal to the emissions they produce.

The law also was the first time Congress laid out a roadmap for how the Environmental Protection Agency would regulate mercury and other toxic air pollution from power plants. Specifically, Congress directed the EPA to find out whether it was appropriate and necessary to regulate mercury and other toxic air pollutants.

“There hasn’t been a material amendment of the Clean Air Act since 1990, so the law that President Bush signed is the one we have been operating under,” Brendan Collins, a partner in the Philadelphia office of Ballard Spahr LLP, told Bloomberg Environment.

A Trip to Rio

Bush also signed the U.S. on to the 1992 United Nations Framework Convention on Climate Change, under which nations first agreed to tackle rising greenhouse gas emissions. He also personally attended the 1992 Earth Summit in Rio de Janeiro, though his role there—to ensure the framework convention didn’t put any specific mandates on the U.S. to actually cut its emissions—led environmental groups to complain he had worked to water it down.

Bush touted the U.N, climate convention, a parent treaty to the 2015 Paris climate accord, as “the first step in crucial long-term international efforts to address climate change” and boasted the U.S. was the first industrialized nation to ratify the measure.

It was an era when Republicans and Democrats alike generally agreed on the need to act.

Sen. Mitch McConnell (R-Ky.), now Senate majority leader and a leading voice in opposing climate action, backed its 1992 ratification, calling the convention “the first step in crucial long-term international efforts to address climate change.”

It also was a high-water mark for Republican presidents on climate action. A decade later Bush’s son, President George W. Bush, would essentially withdraw the U.S. from the Kyoto Protocol, arguing that it only included commitments from industrialized nations and not rapidly developing China and India.

After his 1988 election win, George H.W. Bush installed as head of the EPA someone who would today be considered a surprising choice for a Republican president: William Reilly, a former president of the World Wildlife Fund.

Not all of Bush’s moves were applauded by environmental groups. He created a business-friendly White House body called the Council on Competitiveness that Vice President Dan Quayle chaired and that and worked to roll back environmental rules deemed overly costly to industry.

NAFTA Record

Bush also was crucial in developing the North American Free Trade Agreement (NAFTA), which he signed in 1992 to create a trilateral trade bloc in North America. Reilly at the time called the agreement with Canada and Mexico “the most environmentally sensitive, the greenest free trade agreement ever negotiated anywhere.”

When Bush signed the deal in 1992, opponents of the pact said it would send many American businesses to Mexico because of the country’s comparatively weaker environmental regulations. Critics also weren’t pleased the final text of the agreement didn’t include significant environmental provisions.

To address environmental concerns, the Bush administration pursued a parallel and bilateral environmental agreement with Mexico during negotiations that ultimately resulted in the Clinton administration signing the North American Agreement on Environmental Cooperation.

The side treaty to NAFTA created the Commission for Environmental Cooperation, which has provisions that allow for the enforcement of environmental laws in Mexico, Canada and the U.S.

—With assistance from Amena H. Saiyid and Karn Dhingra.