Because of global warming, permafrost and ice are melting massively at the poles, increasing the sea level at a rate never known before. In a century, the increase reached 18 cm (including 6 cm in the last 20 years). The worst case scenario is a rise of up to 1m by 2100. The acidification of the oceans is also of great concern. In fact, the large amount of CO 2 captured by the oceans makes.