Humans are greening the planet, but the implications are complicated
2016-07-15 10:20:02 GMT
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"'The study shows that humans have caused significant hemispheric-scale changes in vegetation characteristics over the past three decades, predominantly through the physiological effects of increased atmospheric carbon dioxide concentration on plant growth. About one quarter of the carbon dioxide placed annually into the atmosphere by fossil fuel combustion has been hypothesized to be removed through enhanced vegetation growth and accumulation of organic carbon in land ecosystems. This study provides statistically robust evidence that vegetation growth is enhanced by higher carbon dioxide concentrations. Land ecosystems insulate society from some of the consequences of our alteration of the chemical composition of the atmosphere. We showed that increased atmospheric CO2 increases plant growth. Increased CO2 also warms the planet. Increased plant growth is the first step in a process that removes a significant fraction of the human-produced CO2 from the atmosphere, which means there is less warming than if land ecosystems were unresponsive to increased CO2. So, to the extent that planetary warming is a bad thing, the fact that plants are helping remove some of the CO2 that causes the warming is a good thing. '"
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