Expect to hear plenty about Dilma Rousseff in 2011. The former student militant made history on October 31, stomping José Serra to become the first woman elected president of Brazil. Yet even with the wholehearted support of beloved President Lula, she needed a runoff to win, thanks to the real surprise this election season: Marina Silva of Brazil’s Green Party.

President-elect Dilma, who has pledged to be “the Mother of all Brazilians,” was widely expected to avoid a second round by winning an absolute majority back on October 3. She fell a few points shy when Marina and her Green Party drew nearly 20 percent of first-round ballots, defying all expectations and forcing a run-off between the two major parties.

Rio’s daily O Dia hailed the result as a “Green Tsunami,” and overnight, twenty million supporters of Marina’s environmentalist agenda became the hottest voting bloc in Brazil.

Explanations for the Green Tsunami varied. Some speculated that Green Party voters only wanted to extend the debate between the two major parties. Others argued that Marina’s evangelical background and anti-abortion stance were the critical factors. But if the two major candidates’ rush to greenwash themselves is any indication, a new era of Brazilian environmentalism may be on the horizon.

One of eleven children from a rubber-tapping family in the Amazon rainforest, Marina was illiterate until age sixteen. In the 1980s she led demonstrations with martyred environmentalist Chico Mendes, and in 1994 she became the first rubber tapper elected to Brazil’s federal senate.

When Marina began serving as Lula’s minister of environment in 2003, Dilma was minister of mines and energy, en route to a position as chief of staff. Marina resigned from her post in 2008, largely because her Plan for a Sustainable Amazon didn’t jibe with Dilma’s Accelerated Growth Program.

“Sixty percent of Brazil is covered by forest and it is entirely possible to reconcile this with our industry in a way to create jobs and profits without damaging the environment,” Marina has said. “The big challenge facing us as we start this century is to successfully marry up the economy with the environment. And Brazil is the best-placed to do that.”

The emergence of Marina as a force in Brazilian politics is welcome news for anyone who likes oxygen, food, or oil. Already one of the world’s largest suppliers of breathable air, Brazil is an agricultural superpower, poised to become a leading exporter of fossil fuels.

The evolution of Brazil’s environmental policies is vital to the health of the planet as the country balances (or fails to balance) its booming economy with its responsibility as caretaker of 20 percent of the world’s biodiversity.

At least three environmental challenges await Dilma in her first term: proposed reform of Brazil’s Forest Code, rapid expansion of hydroelectric dams in the delicate Amazon basin, and development of vast offshore oil fields.

Marina’s success in the first-round election has already influenced Dilma’s policy priorities. Days before the second-round vote, Dilma released a thirteen-point plan for “Sustainability with Economic Growth,” underscoring previous promises to cut Amazon deforestation by 80 percent and emissions by nearly 40 percent by 2020.

Marina Silva and her Green Party have proven that a new environmental consciousness is on the rise in Brazil. Let’s hope the new president can feel it coming.