yet to come. austin biggest test yet to come. austin hayward, bbc news. wales have the toughest task of them all today but they were leading against the world champions south africa — at the principality... 12—9 the score at half time... dan biggar�*s boot keeping them just ahead... that's all from sportsday. you can get all the latest sports and reports on the bbc sports website. next up on bbc news ros atkins on tree planting. it's no longer controversial to say humans are causing climate change but what we should do about it is less settled. borisjohnson is hosting the cop26 climate summit in glasgow,

and this is his mantra. we can get real on coal, cars, cash and trees. now coal, cars and cash remain difficult, pressing issues. but trees, you'd think they are more straightforward. we know trees absorb carbon dioxide, which is one of the gases that causes climate change, and there are lots of plans to plant more of them. this was donald trump back in 2020. today, i am pleased to announce the united states willjoin 1 trillion trees initiative, being launched here at the world economic forum. 1 trillion trees. and if that's the us, we've seen other big pledges — ethiopia plans to plant 20 billion trees by 2022, china says it will plant 36,000 square kilometres of new forest every year by 2025, and pakistan wants to plant ten billion trees by 2023. but is tree planting really this rare thing, a good idea without a catch?

to many, it's not that straightforward. this is dr bonnie waring... we cannot plant our way out of the carbon crisis with business—as—usual emission scenarios. ..or, as dr kate hardwick at kew gardens in london notes: the risk here is that the benefit of new trees is overstated. there are other risks too — of greenwashing, of damage to ecosystems, of trees distracting from emissions cuts. let's look at all of this, starting with the crucial role that trees play. there are an estimated three trillion trees in the world and they absorb carbon from the air and, crucially, store it.

that's one of the reasons why deforestation has been a focus at cop26. bear in mind, in the last 10,000 years a third of the world's forests have been lost. half of that was in the last century. and if you want to slow global warming, fewer trees doesn't help, and so two policies are being adopted. one is to stop deforestation. the united states will help the world deliver on our shared goal of halting natural forest loss and restoring at least an additional 200 million hectares of forest and other ecosystems by the year 2030. and then the second policy looks to address that forest loss. the commitment yesterday was to sort out deforestation within ten years. in that time, some 70 million hectares of forest will have been disappeared, which is horrendous.

what are we going to do to put that back? so it's not only stopping the deforestation, it's reforesting as well. planting trees — as china is doing here — is the second part of the plan. but look beyond the bold announcements and it's far from clear what mass tree planting will achieve. let's look at the reasons why. well, first of all, planting lots of trees doesn't necessarily mean you end up with more trees. forrest fleischman is a leading expert on mass tree planting. back in september, he tweeted: that's right — almost no impact. and if that's india, then look at turkey. in 2019, a un press release told us that turkey had set a new world record by planting 11 million saplings in three hours.

a few weeks later, the guardian reported up to 90% of the saplings were thought to be dead. just planting trees isn't enough. there are a number of reasons for this. first of all, saplings are vulnerable. around a quarter will die young. second, it takes 20—30 years before a tree will draw significant amounts of carbon dioxide. third, the trees need thinning. without space, a new forest won't thrive. and fourth, if trees die and rot, all of that stored carbon will be released. but even if you do manage a new forest well, there's another issue. this is dr kate hardwick. the point being even if you replace lost forest, the new trees can cause problems.

in one article on mass tree planting, three experts write: so there are questions about which trees are planted, where they're planted, how they're managed. and there's an even more fundamental issue — is there enough space? these are grave doubts, as you can hear. but even if we put them to one side, there's another issue too. here's dr bonnie waring again.

even if we were to cram trees into every corner of the globe where they could possibly grow, we estimate that they would absorb only about ten years' worth of carbon emissions at current rates and it would take them about a century to grow large enough to do so. in other words, neither the volume or the speed is enough. but those who advocate for tree planting don't necessarily say that it is. they argue that trees are one of many ways to help the climate. it's true, trees are crucial for capturing carbon that exists. what's more controversial, though, is that tree planting is also used for something called "carbon offsetting". the idea is that if you cause emissions, you balance this with an action to reduce carbon elsewhere. one example comes from the band coldplay. it wants its next tour to be

as green as possible. here's its lead singer chris martin on one of their ideas. in terms of offsetting people being there, we're able to plant a tree for every ticket sold. coldplay are doing other things, too. and more broadly, offsetting is now widely used by companies and countries as part of their efforts to become carbon neutral. and some, though not all, offsetting schemes involve trees. and there are concerns about how and if this works. take the situation in wales. there are plans there by big business to encourage more tree planting, and those plans are under fire. these companies in england who have a completely different agenda, and that is the carbon—neutral agenda. they will work on behalf of multinational companies, buy up farms in wales and satisfy their carbon—neutral status at the expense of communities in wales. now, the firm in this case here says sustainability is central to its business and that it always consults with local communities,

but the concerns go beyond any one example. some scientists just don't buy the whole idea. mike berners—lee also says this concept is "bogus". greenpeace's language is equally blunt. it describe offsetting schemes as "greenwashing" and "a way for polluters to avoid real emissions cuts". and this perhaps explains why tree planting is so controversial. it's not about if tree planting can make some difference, it's about if it takes a focus away from emissions. and as we consider that, this clip is perhaps useful, of the author fred pearce.

and concern about how trees fit into climate action doesn't mean they're not part of the equation. but as i've made this report, i've kept thinking of this graphic. these are global emissions over the past 100 years. you can see them escalating throughout the 20th century and the year with the most emissions was 2019. 2020 emissions were reduced by covid but this week, scientists reported that global carbon dioxide emissions will rebound towards the level before the pandemic. and while our emissions remain this high, the difference that mass tree planting can make is limited. it also risks creating a reassuring sense of action being taken, when the reality is that carbon levels in our atmosphere need to come down — and quickly. for that to happen will

take emissions cuts, no matter how many trees we plant. whether much windier, already had 50 to 60 mph gusts within the seat in the west and of strong winds with a squeeze on the ice above is just to the south of the low pressure centre this weekend. that really is targeting the windiest weather across northern scotland but today has been a very cloudy day pretty much everyone with not a great deal sunshine on the radar picture we have had rain as well. that rain has been at its heaviest go scotland, northern england, north wales, too, with some patchy rain pushing away has that feature. 0ver with some patchy rain pushing away has that feature. overnight with some patchy rain pushing away has that feature. over night tonight much of that rain will tend to ease

away, the exception across northern scotland where it will continue to be pretty wet and increasingly windy as gusts reached around 60—70 mph, potentially strong enough to bring some localised assumption. it is a frost free night though on account of the cloudy weather and those risk winds. the start of those strong winds. the start of those strong winds across areas of scotland... the winds will tend to ease elsewhere a further amount of dry weather around but i suspect there will be a few showers coming across northern parts of northern ireland for being to the north of wales, north—west england for a time to but otherwise their amounts of dry weather, best of any sunshine across eastern scotland and temperature is 11-14 , eastern scotland and temperature is 11—14 , something like that. looking at the weather chart was monday we have got a bright start a conversation areas, mist and fog patches first then, further west cloudy start, win strengthen and we have got more rain on the way and it

will be working into northern ireland, western scotland and perhaps north england as we head to the day and then that rain eventually moves across the high ground into northern and north—eastern areas of scotland too. temperatures 10—111. north—eastern areas of scotland too. temperatures 10—14 . and then deep into the week ahead it stays unsettled. this weather front threatening bay moves into more central portions of the uk for time on that front max the dividing line between relatively cool air that we have working to the final for the uk to the milder weather we have towards the south. that is today's forecast.

hello, this is bbc news. i'm victoria derbyshire, here are the headlines at seven. former conservative prime minister, sirjohn major, accuses borisjohnson's government of acting in a "shameful" manner — over the 0wen paterson row. i think the way the government handled that was shameful and wrong and unworthy of this or indeed any government. rapper travis scott says he's "absolutely devastated" by the deaths of eight people at the texas festival where he was performing and pledges "total support" to police investigation after a crowd surge. at least 99 people have died in an oil tanker explosion in sierra leone after the lorry collided with another vehicle in the capital, freetown. tens of thousands of people march through glasgow — demanding new steps to tackle global warming — one of more than 100

climate protests taking place across the uk.