The Paris Agreement aims to reduce carbon emissions to zero by 2050, which has sped up the growth of "zero-carbon" business worldwide. Part 3 of Zero Carbon Ahead looks at this trend. The world's biggest solar power station is currently being built in the deserts of the United Arab Emirates -- the power it generates will be far cheaper than coal. Dramatic decreases like this in the cost of renewable energy mean that many businesses hope to eventually use renewables for 100% of their energy needs. P&G, one of the world's biggest consumer-goods corporations, and manufacturing giant GE, which uses AI and smart factories to cut energy use, are 2 such companies featured on this program. China's leader Xi Jinping has spoken about creating an "ecological civilization", and Chinese solar and wind energy firms are pursuing new business abroad. Wall Street and in the US, the financial and insurance sectors are investing vast sums into zero-carbon, despite President Trump's decision to withdraw from the Paris Agreement. Japan is under fire for failing to ride the zero-carbon wave. Fujitsu and other Japanese firms are struggling to achieve low-carbon goals along with their suppliers. The race to reduce carbon emissions to zero is heating up. We report on the latest trends in the world of zero-carbon business.