Record global monthly average temperatures were observed every month from January through August (record monthly temperatures for September, October, November and December occurred in 2015).
15 extreme weather events each costing $1 billion or moreoccurred in the United States (second only to the 16 that occurred in 2011), causing $46 billion in aggregate damages.
The 2016 annual Arctic sea ice extent maximum tied 2015 for the lowest on record, while the annual sea ice minimum tied 2007 for second-lowest on record.
2016 was the first year on record where monthly average concentrations of carbon dioxide (CO2) in the atmosphere never dropped below 400 parts per million. The last time CO2 levels were this high, modern humans didn’t exist, and in the absence of national and international action to reduce greenhouse gas emissions, it is unlikely that CO2 levels will drop below 400ppm again in our lifetime.
Will 2017 Continue the Streak of Record Warmth?
According to the UK Met Office, it’s unlikely that 2017 will be a record-breaker in terms of warmth. One key reason for this outlook is the recent transition from an historically strong El Niño during much of 2015 and 2016 to a current La Niña that is expected to remain or shift to neutral conditions during much of 2017. Among their many implications, El Niño years are typically warmer than average, while La Niña years are cooler than average globally.
So Does this Mean Global Temperatures Will Decline in the Years and Decades to Come?
No. While El Niño and La Niña influence global annual temperatures, it is human-induced greenhouse gases that have driven rising global temperatures over the last several decades. Even with fluctuating El Niño and La Niña conditions every several years, December 2016 was the 384th consecutive month (the equivalent of 32 years) where monthly global average temperatures exceeded the 20th-century average. Further, each of past three decades have successively been the warmest on record, and this decade is well on its way to continue the trend whether or not 2017 unseats 2016 as the warmest on record.
More Important than Ever to Act on Climate Change
The fact that human activities are driving the rise in global temperatures is a consensus among climate scientists and leading scientific institutions around the world (IPCC, NCA, NASA, NOAA, WMO, NAS and UK MET Office). The record-breaking global temperature in 2016 along with the numerous climate records are the latest reminders that it is now more urgent than ever to take comprehensive action on climate change.
With rising global temperatures come tangible impacts and risk. A warmer atmosphere and ocean drive sea level rise and amplify the intensity and frequency of extreme weather, threatening communities, economies and national security. Recent remarks by President-elect Trump backtracking on national and international plans are troubling at a time when we need stronger action. Now more than ever, the United States and the world need to pursue both mitigation and resilience to prepare for the impacts that are already inevitable while best ensuring we avoid the worst of them moving forward. Addressing climate change now can not only save lives, but is a smart investment that can save taxpayer dollars in avoided future damages while building a stronger and cleaner economy.