The list features businesses from around the world that are building technologies to reduce emissions or address the impacts of climate change. They represent advances across a wide range of industries, from agriculture and transportation to energy and critical minerals. One notable difference about this year’s list is that we’ve focused on fewer firms—we’ll highlight 10 instead of the 15 we’ve recognized in previous years. This change reflects the times: Climate science and technology are in a dramatically different place from where they were just one year ago. The US, the world’s largest economy and historically its biggest polluter, has made a U-turn on climate policy as the Trump administration cancels hundreds of billions of dollars in grants, tax credits, and loans designed to support the industry and climate research. And the stark truth is that time is of the essence. This year marks 10 years since the Paris Agreement, the UN treaty that aimed to limit global warming by setting a goal of cutting emissions so that temperatures would rise no more than 1.5 °C above preindustrial temperatures. Today, experts agree that we’ve virtually run out of time to reach that goal and will need to act fast to limit warming to less than 2 °C.