Several major corporations, including Amazon, Ford, and General Motors, have announced a new pledge to achieve net-zero greenhouse gas emissions by 2050. The companies, which together represent more than $1.5 trillion in revenue, have joined the "Business Ambition for 1.5°C" campaign, which aims to limit global warming to no more than 1.5 degrees Celsius above pre-industrial levels. The pledge includes a commitment to set science-based targets for reducing emissions and to work towards using 100% renewable energy. The move is seen as a significant step in the fight against climate change and could put pressure on other corporations to follow suit.