one of them for this is professor tom crowther from the swiss federal institute of technology in zurich welcome to day w didn't we already know that trees absorb carbon dioxide and there are lots of tree planting schemes already out there to offset environmental damage. yes you're exactly right we've known that trees are an amazing carbon trap from the last well over the last century and there are projects out there trying to promote restoration but what this new study shows is actually we've got the 1st quantitative understanding of how much that can achieve and it's actually 10 times more than we previously expected placing restoration far far higher than the next best climate change solution so it's really about figuring out the best ways to allocate our resources and now we know that restoration is a powerful way a trillion trees sounds like an awful lot how much space is that going to take why would they go. so that's what we've modeled as way trees can exist on the planet and when you subtract away existing urban land and agricultural land we're left with the world's degraded land

from the swiss federal institute of technology in zurich visits the mountains twice a year once in spring and again in autumn when the season begins. they investigate how much fresh snowfall there was in winter and the fitness of the snow cover over the ice the more snow there has been the better the condition of the glazier today the 25th of april 28th seen it's in better shape than it's been for a laugh. more than 5 metres of snow fell in winter. jamba itself. we've measured snow water equivalent at 7 glaciers across what's. our measurement showed that in 2018 snow cover was well above average. and there wasn't quite as much snow depth everywhere and switzerland as there was here but it doesn't look like there was perhaps as much as 50 percent more than a normal year at st neots also not manyara. latinos horse will be back in autumn. there are plenty of people who see the healthy snow fall as proof that climate change is a mess. but in europe's high mountain ranges the evidence is all around in italy switzerland austria slovenia and germany. the environmental research station she found

in the scientists that we just saw in that report john francoise best known of the swiss federal institute of technology in zurich it's good to have you on the program ok we're talking about a trillion new trees i mean that that that is a lot of trees is there really enough space on the planet where conditions where there is space and where the conditions are just right to grow trees well this is what we did in our study basically it's the 1st time that 3 minutes ready to quantify to that of these quanta that this quantitative approach scares me to know what can be done on the planet and the thing is that modern which is predicting where we can put back some trees in the natural environment and not try to call system is only based basically on priming that down to but i think that's how and i think that that's basically just on this coming nation of about a viable those that we observed in natural conditions were able to see that cocaine and natural condition with those variables we can have that amount of trees and this is based on that we're able to extrapolate to an older condition all of underworld

he is of the swiss federal institute of technology in zurich. are talking about one trillion new trees. that is a lot of trays. is there really aon the planet where conditions are just right to grow trees? >> this is what we did in our study. it is the first time we managed to quantify what could be done on the planet. our model is only based on climate data. on this combination of variables that we observed in natural conditions. we can have that amount of trays. -- trees. just based on those conditions. brent: is there a certain type of tree that is better for helping to fight climate change? >> it allows me to make an important point. the idea that we are defending his we need to restore the natural ecosystem. we do not support the idea of planting eucalyptus or pine trees everywhere around the globe. we can restore the natural ecosystem. we need to respect the local species to preserve the local biodiversity. all of the forest ecosystems shelter 80% of the biodiversity we can find on land. it is very important to respect local conditions. br