Sea ice plays a crucial role in cooling the planet by trapping existing heat in the ocean, and thus precluding it from warming the air above. Therefore, a reduction in sea ice cover can have disastrous consequences for Earth. https://indianexpress.com/article/explained/explained-climate/why-global-sea-ice-cover-has-dipped-to-record-low-what-this-means-9845380//?ref=expin