henri perrot-minot has spent his life in the vineyards and wine cellars.emembers the way things were in the past, and worries about the future of burgundy wine. for decades, he's been meticulously noting the starting date of the annual grape harvest. in the 1970's and 1980's, it almost always began in october. >> in 2014, we started on september 17th. and this year? on september fifth. >> we've seen that the harvest is starting earlier every year. the grapes take 100 days to ripen. and now, the vines are starting to bud in the spring. reporter: the two vintners are satisfied with the 2014 vintage, despite their concerns about the earlier harvest. hot summers -- or any unsually hot temperatures -- affect the grapes. >> they burn, because it's too hot for them. >> they're baked in the sun when temperatures rise above 35 degrees celsius. we first noticed this in the 1990's, and i asked my grandfather about it. we thought it was some new disease. but it wasn't. reporter: extreme weather conditions are on the rise in france's wine-growing regions. these vines h