Globe goes green (as pollution makes it sicker)

As leaders from 170 countries (and Leonardo DiCaprio) attended a ceremonial signing of the landmark Paris Agreement at the United Nations HQ on Earth Day, new research revealed that nature has responded to manmade climate change in its own astonishing way, with trees and plants around the planet turning over a new leaf—millions of new leaves, in fact, enough to cover the US in a giant green carpet twice over.

According to analysis of data captured by instruments aboard satellites orbiting the world, Earth is literally becoming a much greener place as a direct result of all the carbon dioxide being spewed out by our modern industrial society.

Graphic by Boston University/R.Myneni, source: The BBC
Graphic by Boston University/R.Myneni, source: The BBC

The phenomenon is explored in a report called Greening of the Earth and its Drivers, published in the journal Nature Climate Change and written by a team of 32 authors from 24 institutions in eight countries. It explains how images taken from space over the last three decades show trees and plants mopping up rising levels of CO2 pollution by producing more leaves and sprouting in new areas.

The increased level of greening is between 25% and 50% of the Earth’s vegetated land, and the main reason this is happening, according to the scientists, is that plants are lapping up all the extra CO2 human society is producing and using it to fertilise their growth.

As plants suck damaging CO2 out of the atmosphere and convert it into oxygen, they are slowing the pace of climate change. So that’s the good news. The bad news is—despite the claims of some climate change deniers—this sterling effort is not going to stop global warming all by itself.

Lead author of the report, Professor Ranga Myneni from Boston University, cautioned the BBC that various other factors will inevitably see temperatures continue to rise—as they have done alarmingly so this year, breaking records every month— with sea levels getting higher, glaciers melting and severe tropical storms getting worse and more regular.

The fertilisation effect will wane over time, the scientists warn, and as the globe warms, increased levels of CO2 will be released by decomposing organic matter, thawing permafrost and rapidly drying soils.

Exeter University’s Professor Pierre Friedlingstein, who worked on the report, confirmed that Intergovernmental Panel on Climate Change (IPCC) models do factor in carbon uptake from plants, but conceded that it is a source of uncertainty in future climate forecasts.

‘Carbon sinks—such as forests, where carbon is stored—would become sources if carbon loss from warming becomes larger than carbon gain from fertilisation,’ he explained. ‘But we can’t be certain yet when that would happen. Hopefully, the world will follow the Paris Agreement objectives and limit warming below 2C.’

So all we need now is for mankind to show as much willing and effort as the plants we share the planet with, by turning over a new leaf of our own.