Ice reveals increased plant growth

07 April 2017

Scientists have created a new method to assess how plants react to changes in the atmosphere. The research, conducted at the Sierra Nevada Research Institute, showed that during the industrialisation of the last century, plant growth increased by over a third and this is a useful benchmark for understanding how plant growth will continue to change as we burn more fossil fuels in the future.

As a planet, fossil fuel consumption accounts for the release of 9 Giga tonnes of greenhouse gas carbon dioxide into the atmosphere every year - a key driver of climate change. The good news is that plants uptake carbon dioxide in order to produce sugars which provide them with energy. So plants, to some extent, are mitigating the extent of our greenhouse gas emissions.

Using Antarctic ice samples that contained gasses trapped since the 1900s, the group measured levels of a gas called carbonyl sulphide, which acts as a marker for photosynthesis. They found that these levels didn’t increase as much as expected, despite the rise of industries producing carbonyl sulphide as a by-product. The gas is emitted by factories making coal and aluminium for example, and even Rayon - the key material in the classic Hawaiian shirt!

So the question is where did all the gas go? The scientists believe that its disappearance is down to plants, which take up carbonyl sulphide in the same way that they take up carbon dioxide. So as industrialisation increased, so did plant growth, but not nearly enough to compensate for our increased emissions. Plants are only capable of taking up about two parts of carbon dioxide for every ten we emit. In fact, some models predict that in as little as 50 years, the capacity of Earth’s plants to absorb carbon dioxide will be so overwhelmed that they could start actually emitting it themselves and compound the problem.

This new estimate, published in Nature, gives scientists a reference point from which to rate other climate change models. By understanding how plants responded to atmospheric changes in the past, further studies can better predict how they will react to changes in the future.


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