Blue and Green: Billionaire climate activist Tom Steyer has said he will target the campaigns of seven US senate and governors this year, in an attempt to make climate change a top priority in Novembers elections. He is prepared to spend up to $100m (59m) in his quest. The seven elections in Florida, Colorado, Iowa, Pennsylvania, New Hampshire, Maine and Michigan all feature Republicans that have denied climate change or received donations from the fossil fuels industry. Steyer will use $50m (29m) of his own...