Answer:
Step-by-step explanation:
Framed in this way, the problem of climate change becomes not one of simply producing greenhouse gas, but how quickly we do so when compared with the Earth’s natural ability to soak it up again. And it makes that natural ability – the continuing capacity of forests and oceans to act as carbon sinks – as significant a factor in deciding the likely course of rising temperatures in the near future as intended controls on our greenhouse gas emissions. Yet many people are unaware of this side of the carbon balancing equation. And if they are, they take it for granted – they expect that forests and oceans and other carbon sinks will continue to act as our environmental get-out-of-jail-free card.
Or, more accurately, our go-to-jail-slightly-slower card. While sinks have managed to grab about half the carbon released as human pollution in recent centuries, the rest steadily accumulates in the atmosphere. The forests and oceans simply can’t suck it in fast enough. At the last count, atmospheric levels of carbon dioxide registered almost 412 parts per million (ppm) and rising. That’s a 47 per cent jump since the beginning of the industrial age, when the concentration was near 280 ppm, and an 11 per cent rise since just 2000, when it was near 370 ppm. Without our natural carbon sinks working to buffer the impact, that figure would probably be closer to 700ppm today.
It makes sense, then, that the future behavior of Earth’s massive carbon sinks – and specifically the question of whether they will continue to bail us out by taking in carbon dioxide – is a key topic of research for scientists. How will tropical forests respond to warmer temperatures? Will ocean currents continue to carry carbon to the depths? What happens to the pace of climate change if the carbon-catching capacity of these sinks weakens?