On a balmy day in November 2015, President Obama did the right thing and rejected the Keystone XL pipeline once and for all. Although I am well aware that this is just one battle in an on-going war, still it seems worthwhile to pause a moment to savor this victory.

At the climate change rally in Washington DC, Feb. 2013

Back in February 2013, I traveled to Washington DC with friends to participate in the historic protests against the Keystone XL. President Obama was conveniently absent the day we circled the White House with our protest parade, but the rally was the largest ever demanding that our politicians start taking climate change seriously, and we left D.C. the next day feeling satisfied that we had done our best to get our point of view across.

And now here we are at the hottest November ever; the glaciers and poles are melting at alarming rates; and there are dramatic die-offs of marine life as the oceans warm, turning, as one headline put it, into “cauldrons.”

Terrestrial life is similarly stressed, with mysterious mass deaths in Central Asia and raging, out-of-control fires burning in Indonesia. In the Middle East drought conditions persist, and it has been alarmingly hot—with predictions that by 2070, large portions of the Gulf peninsula will no longer be habitable for humans.

I was especially disturbed by a recent New York Times op-ed arguing that the time for climate change mitigation is past, and we must now do our best to adapt to the inevitable rapid heating of the planet.

“Drastic reductions would be needed to stabilize human influences on the climate at supposed “safe” levels,” writes scientist Stephen E. Koonin. “According to scenarios used by the United Nations Intergovernmental Panel on Climate Change, global annual per capita emissions would need to fall from today’s five metric tons to less than one ton by 2075, a level well below what any major country emits today and comparable to the emissions from such countries as Haiti, Yemen and Malawi. For comparison, current annual per capita emissions from the United States, Europe and China are, respectively, about 17, 7 and 6 tons.” And “even if today’s annual per capita emissions of three tons in the developing world grew by midcentury to only five tons (about 70 percent of Europe’s per capita emissions today), annual global emissions would increase by 60 percent.”

So are we doomed then? Will the world as we know it be swept away by the dramatic climate shifts ahead of us?

It’s impossible to deny the very real possibility that global warming will cause the collapse of many of the life support systems that have made human beings so incredibly successful as a species.

We are over-populated, and Mother Earth has ways of dealing with such imbalances. The only way to avoid serious system collapse is to dramatically recalibrate our relationship with the Earth. It’s not rocket science: we know that we need to leave fossil fuels in the ground, shift to renewable energy like solar, geothermal and wind, and stop deforestation. And while we’re at it, reduce our chemical dependency and shift food production into permaculture practices. Stop raising and eating so much meat, and shift to healthier plant-based diets.

We must continue to pressure our politicians to make the policy changes needed to support these crucial shifts (and another piece of good news is the possibility that Exxon-Mobil and other fossil fuel giants may be sued for lying to the public about the dangers of climate change–what I myself would call CRIMES AGAINST HUMANITY).

Tonight, I raise a glass to toast Bill McKibben, 350.org and all the environmentalists who worked so hard for today’s rejection of the Keystone XL pipeline.

It is a wonderful victory, but we still have a lot of work to do before we can rest easy knowing that we have done our part to assure that our grandchildren will inherit a habitable world.