给你一个包含多个句子的英文段落，请告诉我它的主题和基本思想。

The global climate is changing due to human activities, such as burning fossil fuels and deforestation. This has led to rising sea levels, more extreme weather events, and loss of habitats for millions of species. It is urgent that we take action to reduce carbon emissions and protect the environment for future generations.
主题：气候变化和环境保护。

基本思想：人类活动导致气候变化，应采取行动减少碳排放和保护环境。