If we stop our emissions today, we won’t go back to the past

In 2017, there’s been a stunning decrease in Antarctic sea ice, reminiscent of the 2007 decrease in the Arctic.

What would happen to the climate if we were to stop emitting carbon dioxide today, right now? Would we return to the climate of our elders?

The simple answer is no. Once we release the carbon dioxide stored in the fossil fuels we burn, it accumulates in and moves among the atmosphere, the oceans, the land and the plants and animals of the biosphere. The released carbon dioxide will remain in the atmosphere for thousands of years. Only after many millennia will it return to rocks, for example, through the formation of calcium carbonate – limestone – as marine organisms’ shells settle to the bottom of the ocean. But on time spans relevant to humans, once released the carbon dioxide is in our environment essentially forever. It does not go away, unless we, ourselves, remove it.

In order to stop the accumulation of heat, we would have to eliminate not just carbon dioxide emissions, but all greenhouse gases, such as methane and nitrous oxide. We’d also need to reverse deforestation and other land uses that affect the Earth’s energy balance (the difference between incoming energy from the sun and what’s returned to space). We would have to radically change our agriculture. If we did this, it would eliminate additional planetary warming, and limit the rise of air temperature.

A scientist writes : "As a professor of climate and space sciences, I teach my students they need to plan for a world 4℃ warmer. A 2011 report from the International Energy Agency states that if we don’t get off our current path, then we’re looking at an Earth 6℃ warmer. Even now after the Paris Agreement, the trajectory is essentially the same. It’s hard to say we’re on a new path until we see a peak and then a downturn in carbon emissions.

If we stop our emissions today, we won’t go back to the past. The Earth will warm. And since the response to warming is more warming through feedbacks associated with melting ice and increased atmospheric water vapor, our job becomes one of limiting the warming."

Acknowledgement : Sourced entirely from this link.