It's a brand new year and we can expect it to bring climate challenges, both new and old. Most of the predictions for climate change in 2013 and beyond build upon the trends we have seen over the past years, and especially in 2012 — from Hurricane Sandy to the hottest month on record.
Climate is an average of the weather we experience every day — the climate influences the probability of certain weather events, but it does not make them a certainty; making predictions about the impact of climate change in any given year cannot be done with 100% certainty — typically, the best we can do is say what is likely (even that can be challenging). Yet there are several factors related to climate change for which we are relatively sure what will happen:
1) It will keep getting warmer: And we will keep breaking temperature records. Many scientific papers have found an upward trend in temperature records, which averages somewhere around 0.16 degrees Celsius per year; indeed, this is the signature effect of climate change, so much so that this global warming prediction almost goes without saying.
This warming trend is obscured by the variability of day-to-day weather, and by noise that can largely be attributed to three sources – solar activity, El Niño, and volcanic activity – but it is relatively straightforward to remove those effects and reveal the underlying trends attributed to global warming. These trends have been confirmed in many ways, most notably by satellite observations that show more heat entering the atmosphere than exiting it due to atmospheric gases (i.e. greenhouse gases), which would lead to the observed warming in the thin coat of air that we call home.
El Niño is associated with global temperature maximums approximately 4 months after the event, as effects of the ocean's heat release are felt. El Niño conditions are not currently predicted to develop in 2013, but if it does happen, expect it to contribute to more record-breaking high temperatures. For more information, Stefan Rahmstorf, a prominent climate scientist, offers a wonderfully clear explanation of climate change, El Nino, and solar activity on Slate.
2) Droughts will persist: Notably in the U.S.' southwest. The Southwest has seen devastating droughts in the past year, and they are expected to intensify in 2013, according to the National Oceanic and Atmospheric Administration (NOAA). Climate change will continue to make such droughts more likely into the future, as well; watch this video from Climate Central for a quick primer on the link between drought and climate change.
3) Artic Ice coverage will again be very low:
On September 16, 2012, a record minimum was set for Arctic sea ice – both in ice extent and volume. That means that a huge portion of the ice in the Arctic this winter is first-year ice, especially since large quantities of older ice melted in 2012. The younger ice is thinner and melts more rapidly in the summer than older ice. These conditions make the Arctic more susceptible to significant ice depletion in 2013; even if it does not set a new record, it is very likely that ice coverage will be startlingly low again. Overall trends suggest that the minimum Arctic ice extent is decreasing by 13% per decade.
4) Summer will be a little longer: Fall will keep coming later, and spring earlier. The leaves stay on the trees approximately 10 days longer now than they did in the early 1980s in the United States. Spring has likewise been arriving earlier and earlier over the last half-century, as measured by the arrival of new leaves. Both of these seasonal shifts have their roots in an increase in average temperature; the length of the day and rainfall patterns also affect seasonal changes, leading to plenty of inter-annual variability. However, the overall trend points towards a longer summer in the future.
5) Storms and sea level rise: will continue to put low-lying costal areas at risk.
Climate change brings the forbidding threesome of rising sea levels, more storm-surge-causing weather, and more intense rain. These three factors put low-lying areas at risk – as New York and New Jersey learned only too well this past hurricane season. Such weather-triggered events cannot be predicted in advance, but climate change makes them increasingly likely. Average sea level has risen approximately 8 inches since 1880, and will continue to rise. Low-lying island nations have felt these impacts acutely, and in 2013 will continue to see increased flooding of their fields and homes – if they haven't already been forced to relocate.
In the face of such continuing challenges, we can also expect those working to promote solutions – from scientists to politicians, from solar cell designers to activists, to continue fighting in 2013 against climate change's impacts and causes. If you procrastinate like me and still haven't gotten around to finalizing your new years resolutions (and even if you have!), consider adding to your list the resolution to do your part against climate change in 2013.