reporter: this is richard muller and his daugherty elizabeth, a mathematician are not exactly house holes names. in the world of climate change where most scientists and a match smaller group of skeptics remain bitterly divided over their assessment of what's happening to the planet, richard muller has long been on the side of those who deny climate chan is happening. when he published an op-ed in

reporter: this is richard muller and his daugherty elizabeth, a mathematician are not exactly house holes names. in the world of climate change where most scientists and a match smaller group of skeptics remain bitterly divided over their assessment of what's happening to the planet, richard muller has long been on the side of those who deny climate change is happening. when he published an op-ed in the ne "new york times" last moh saying he was no longer a skeptic, it captured national attention and sparked angry reaction on both sides of the climate fence perhaps most disturbing to some of his former allies was this conclusion. >> in our world, we attribute the warming from 175 to the present... 1753, to the present exclusively to humans not mostly. >> reporter: even those skeptics who accept that the climate is changing attribute it to natural cycles, but muller even claimed his study was more conclusive in that regard than any that came before. >> we really are in some sense coming out with a stronger conclusion than the prior group had come out with. >> reporter: working out of their

richard muller and his daughter elizabeth, who researched the topic. that's on our home page. also, we point to much more of our coverage on climate change with links to several of the stories we've produced in the past. plus, tonight's edition of "frontline" follows rebel fighters in aleppo, syria, during the bloody month of august. find a link to "the battle for syria" on our web site. all that and more is at newshour.pbs.org. judy? >> woodruff: and that's the newshour for tonight. on wednesday, we'll look at myanmar's pro-democracy leader, aung san suu kyi, as she receives congress' highest civilian honor. i'm judy woodruff. >> ifill: and i'm gwen ifill. we'll see you online, and again here tomorrow evening. thank you, and good night. major funding for the pbs newshour has been provided by: >> bnsf railway. >> intel. sponsors of tomorrow. >> and by the bill and melinda gates foundation. dedicated to the idea that all people deserve the chance to live a healthy, productive life. and with the ongoing support of these institutions and foundations. and... this program was made