For Americans concerned about the environment, disaster was avoided on Tuesday. President Obama – with his somewhat lackluster record, if decidedly more exalted rhetoric, on global warming – defeated the Republican challenger who had vowed to gut federal emissions standards, and kill loan programs and tax breaks for green energy companies.

But activists say that it would be wrong to read the election as a stamp of approval for four more years of business as usual. They argue that voters have sent a clear signal that they want more aggressive action on the environment during the president’s second term.

The League of Conservation Voters (LCV) cites the defeat of three members of their “Flat Earth Five” – Anne Marie Buerlke (Republican, New York), Francisco Canseco (Repub;lican, Texas) and Joe Walsh (Republican, Illinois) – Republican representatives who were outspoken for their anti-science stance on climate change. (One race remains too close to call.) And ten of the League’s “dirty dozen” candidates – targeted for “consistently voting against clean energy and conservation” – lost their election bids.

Meanwhile, 11 out of 12 of the office-seekers dubbed “climate heroes” by a coalition led by environmental activist Bill McKibben, prevailed in Tuesday’s vote. The 12th “hero”, Jay Inslee, a gubernatorial candidate in Washington state who wants to jump-start the state’s lagging economy by transforming it into a national green-tech hub, continues to hold a small lead over Republican Rob McKenna and looks poised to win that race.

The election results overturn the conventional wisdom that voters don’t care about green issues, according to LCV’s spokesperson Jeff Gohringer:

“We went into this election cycle and the notion was that environmental champions were going to be wiped off the map. We did $3m-worth of advertising on climate change in places like Texas, and we won.”

This sentiment was echoed by Frances Beinecke, the president of the Natural Resources Defense Council who wrote to her members on Wednesday that:

“By rejecting Big Oil’s candidates, voters sent a message loud and clear that they want more clean energy, less climate denial and an end to the $4bn in taxpayer subsidies for fossil fuels.”

Some environmentalists have characterized Obama’s very re-election as a mandate for strong action on climate change. This is a hard argument to make given that the topic scarcely came up during the presidential race. Obama, who frequently expressed concern about the climate during his first run for the presidency in 2008, failed to talk about it on the stump this time around. The president’s campaign advisers apparently calculated that there were few votes to be won, and potentially many to be lost, if Obama were to appear to advocate tougher regulations on industry at a time of low economic growth and high unemployment in America.

Romney attacked Obama in TV ads broadcast in the swing state of Ohio for what he characterized as “job-killing” regulations on coal, which is a big player in mining and electricity production in much of the midwest. But the president’s bailout of the auto industry turned out to have been more persuasive to voters in the “rust belt” states, which went solidly for Obama on Tuesday.

With the candidate’s relentless focus on the economy, climate change was a non-issue – until Nature herself brought it savagely into focus with Hurricane Sandy, the largest and most destructive weather event on record for the mid-Atlantic states. Climate scientists have been saying for years that warmer ocean temperatures, together with rising sea levels, would lead to an increase in punishing hurricanes. This prediction has tragically proved accurate ever since Hurricane Katrina, which killed over 1,800 people in New Orleans in 2005.

Many political observers called the latest storm, Sandy, “a game-changer” in Tuesday’s election. It gave Obama a chance to “act presidential”, touring the coast of New Jersey with the state’s grateful Republican governor, Chris Christie, at a critical moment just days before the vote. It also earned the president a timely endorsement from New York City Mayor Michael Bloomberg, who applauded Obama for acting to stem climate change, taking steps to raise the fuel-efficiency standards on cars and tighten pollution rules on power plants.

Americans’ views on global warming shifted markedly during the past summer, which saw record heat waves and drought in over two-thirds of the nation. As I reported in the Guardian last month, a Brookings survey conducted in July indicated that over 70% of Americans believed that climate change is happening, up from the 52% who held that view in 2010.

The number of climate-change believers has undoubtedly risen still further since Superstorm Sandy, which powerfully demonstrated that global warming is not a theory about the indeterminate future, but a snowballing catastrophe that is with us right now. A study by insurance giant Munich, released days before Sandy struck, reported that North America has suffered $1.06tn in extreme weather damage since 1980. That mind-boggling number is five times the average loss in prior decades.

It is perhaps no coincidence that six of the critical swing states which President Obama won – Colorado, Iowa, Ohio, Virginia, New Mexico and Wisconsin – all suffered an uptick of extreme weather events, including massive tornados and crop-destroying drought, within the past year. ThinkProgress reports that oil and gas companies, and political PACs poured in $270m to pay for TV ads in support of Mitt Romney and other, mostly Republican candidates. Billionaire oil magnates, the Koch brothers, added $400m of their own funds to the GOP kitty. With so many of its favorites going down in defeat, however, these fossil-fuel advocates have virtually nothing to show for their whopping investment.

Environmental activists are urging President Obama to harness his victory at the polls to enact stringent new limits on CO2 emissions, and to push hard for concerted global action on the climate. In one of his first references to the threat of climate change since the convention, the president warned of “the destructive power of a warming planet” in his victory speech in Chicago.

But Obama will, undoubtedly, face the same opposition in Congress in the next four years as he did in the last. Republicans in Congress last year voted no fewer than 247 times (nearly once a day for every day the House was in session) to weaken EPA protections that have been in place for decades, and to defeat proposed new climate legislation. This led Representatives Henry Waxman and Edward Markey to issue a report in June that called the 112th Congress the most anti-environment in history.

That is the bad news. The good news is that, if the election results are to be trusted, the public’s patience for Republican obstructionism on the environment may have just run out.