The growing severity and frequency of extreme-weather events suggests that climate scientists’ nightmare scenarios must be taken seriously. Fortunately, rapid advances are being made in clean-energy technology and carbon-neutral forms of living... But there is another risk: that warnings such as these will lead to despair.. political and technological developments that are currently underway offer grounds for genuine hope... the real focus was on the Exponential Climate Action Roadmap, a major new study showing that progress in the use of non-fossil-fuel technologies is advancing not just linearly, but exponentially.. solar- and wind-power usage is doubling every four years. If that continues, at least half of global electricity production could come just from these two forms of renewable energy by 2030. And there is no good reason to think that progress couldn’t accelerate further. Just in the past few years, there have been rapid advances in solar-energy technologies and energy storage... $90 trillion will be invested in new infrastructure around the world over the course of the next 15 years... humanity could have an historic opportunity to leapfrog into far more sustainable, carbon-neutral patterns of habitation... New approaches to energy, industry, architecture, city planning, transportation, agriculture, and forestry have the potential to halve GHG emissions by 2030... GHG emissions have already peaked in 49 countries that account for 40% of global emissions; and ten countries have even committed to being carbon-neutral by 2050. California and Sweden say that they will produce zero net emissions by 2045.