There are a variety of indicators that show our climate is changing, including increasing average temperatures, melting glaciers, and sea-level rise. Nevertheless, it is extreme events, such as record heat, that usally garner the most attention.
Around the globe, the number of record high temperatures are out-numbering record low temperatures. In the US, according to an analysis by the AP, record warm days have out-paced record cold days by a ratio of 2:1 since 1999. This is a clear sign of our climate is shifting to a “new normal”.
In a stable climate, record highs and lows would be more balanced, with the ratio being closer to 1:1.
While climate change is a global phenomenon, we can see it playing out at a local scale. Here in New York City, we still get the occasional cold snap in winter, but the record highs have been outpacing the record lows for decades.