What we need to do to survive

This weekend, I stood at the corner of 65th and Broadway in New York City and I thought of Marium. The occasion was the People's Climate March – a huge protest designed to call attention to the climate change disaster. The march was timed for just before the UN Climate Summit, a meeting of some 125 heads of state on averting the impending catastrophe of planetary warming, sea level rise, and land loss.

The march billed itself as the "largest march against climate change in history," and it was. Some 400,000 people attended to ask the UN to impose regulations on carbon emissions. Many powerful people chose to join them, including Al Gore, the former US Vice President, and Ban Ki-moon, Head of the UN. At 65th, gathered at the edge of Central Park in a crowd of protestors representing South Asian nations was Saleemul Huq – head of Bangladesh's International Center on Climate Change and Development, and one of 38 dignitaries who addressed the UN Climate Summit on September 23.

Mr. Huq is an affable professional, knowledgeable and well-spoken about his field. Shaking his hand in the midst of the protest march, though, I didn't think of the UN Summit, nor ask Saleemul bhai about the policies he will ask the UN to enforce. Instead, for a moment, I thought about a woman I know in Dhaka – and about what climate change means for her.

Marium is the mother of a friend of mine. (I have given her a pseudonym here.) She has lived in Dhaka with her family nearly all of her life, including every single day of 1971. She outlasted that horrific genocide somehow (although her story, like so many others, remains mostly private). She has since weathered a few tragic deaths among her immediate family, and was widowed of her husband several years ago. She is, in her own way, a matriarch now. She is also a survivor in every sense of the word.

At age 70, she should be done weathering tragedies. Yet I worry about her. In New York, I wondered if, with climate change advancing, she might end up facing a situation as grave as 1971 all over again. I wonder if life as it is today might soon change dramatically for her in Dhaka.

Life in Bangladesh already has changed, of course. Marium's younger son once told me that he can remember a time when hail – precipitation that falls in the cold season as chunks of ice, not raindrops — would happen in Dhaka. The idea of ice falling from the sky above Dhaka's humid mass of factories and flyovers is now almost beyond imagining.

Soon it may be completely unimaginable. Two degrees Celsius, they say, is the greatest temperature increase we could sustain without great disaster being unleashed across the planet. Marium's son is just old enough to remember something that no one under thirty years of age has ever experienced: a month colder than average. For 360 consecutive months, the global temperature has been rising and rising – growing closer, month by perilous month, to the highest margin we can survive. We have, at this point, the narrowest of margins to achieve real change. As International Energy Agency chief economist Fatih Birol says: "The door to reach two degrees is about to close. In 2017 it will be closed forever."

Marium, like almost all other Bangladeshis, will bear no blame for that. Indeed, the country has done nothing to cause climate change. As a statement from Huq's Bangladesh Environment Network to the UN Climate Summit says, "Bangladesh's share in the cumulative [carbon] emissions since the Industrial Revolution is close to zero percent."

Yet low-lying Bangladesh is quite vulnerable. Whether or not humanity moves back from the edge by then, Bangladesh will suffer some climate change effects. This is inevitable; already, hot weather is challenging the survival of plants and animals around the world. One meter of sea level rise, the level that climate scientists now say is inevitable. But at that rate, low-lying Bangladesh will lose nearly 17% of its total landmass over the next few decades. With one meter of sea level rise, Sundarbans will be drowned, and millions of people will be forced to move from southern Bangladesh into Dhaka, Rajshahi and Sylhet Divisions.

For Marium at home in Dhaka, the changes might include suffering through endless heatwaves; withstanding intense monsoons that surpass Dhaka's current routine flooding; and enduring the food insecurity that might arise when excessive heat makes crops fail. It might mean facing decreasing quality of life as waves of migrants arrive from the south, crowding the already-crowded city. It could mean needing to leave Bangladesh.

Some say that there are opportunities for positive change right now, including new businesses and better social structures. One group amid the South Asian contingent of the People's Climate March carried a banner reading "Decolonize the Climate." It was a reference to the way the developing world bears an excessive proportion of climate chaos that the West caused, and a demand for the lingering shadow of Western imperialism to be wiped away amid the sweeping changes the world must make now.

Walking along the edge of New York's leafy green Central Park this Sunday, I saw a river of people who are willing to take responsibility to prevent as much of that as possible. We still have a narrow chance to avert total disaster – and we know that the change must come from countries like America, where wealthy people's consumer habits drive the carbon emissions that heat the planet. At the People's Climate March, hundreds of thousands announced that they were ready to change. One man hoisted a sign that put the mission bluntly: "Do what must be done so that we survive."

For Bangladesh, what needs to be done are not just marches. Serious efforts to plan for coming changes likely mean policies to capture UN funds for climate mitigation and adaptation, and wise use of that money. This means a national dialogue about what is happening and will happen, heavy attention to mitigation and adaptation, and real help for the many people who will leave their rural land for the cities. Several political leaders are already engaged in that work, including Saleemul Huq and Sheikh Hasina. It would be wise to add many more voices, much more often, starting as soon as possible.

Huq is optimistic that the necessary changes will be made. I hope so. Like some 400,000 other people, I feel committed to climate action on Bangladesh's behalf, although I believe it will be tremendously challenging. I am keeping my respect for people like Marium, who already endured a great burden to create Bangladesh, in mind.