Our prettiest pollutant: just how bad are fireworks for the environment?

Paul Brock Photography/Flickr, CC BY-NC-ND

Gary Fuller, King’s College London

Fireworks are great fun. We all enjoy guessing the colours of the rockets before they ignite in the sky, hearing the explosions echo off nearby buildings, or writing our names in light with hand sparklers.

But there is an environmental price to pay. Firework smoke is rich in tiny metal particles. These metals make firework colors, in much the same way as Victorian scientists identified chemicals by burning them in a Bunsen flame; blue from copper, red from strontium or lithium, and bright green or white from barium compounds.

Narwhals and other unique animals are at risk

Donna Hauser, University of Alaska Fairbanks; Harry Stern, University of Washington, and Kristin Laidre, University of Washington

Most Americans associate fall with football and raking leaves, but in the Arctic this season is about ice. Every year, floating sea ice in the Arctic thins and melts in spring and summer, then thickens and expands in fall and winter.

As climate change warms the Arctic, its sea ice cover is declining. This year scientists estimate that the Arctic sea ice minimum in late September covered 1.77 million square miles (4.59 million square kilometers), tying the sixth lowest summertime minimum on record.

Crops could face double trouble from insects and a warming climate

Gregg Howe, Michigan State University and Nathan Havko, Michigan State University

For millennia, insects and the plants they feed on have been engaged in a co-evolutionary battle: to eat or not be eaten. Until recently, the two antagonistic sides have maintained a stalemate of sorts. With climate change, however, warmer temperatures could tip the balance in favor of the insects and spell danger for crops and the farmers that tend to them.