Communicating about Tropical Cyclones and Climate Change: Science talking points

Shared by Interfaith Power and Light

One of the clearest and most devastating impacts of climate change has been the dramatic amplification of damage done by hurricanes/tropical cyclones.

Sea level rise to date has elevated storm surge, increasing the reach of coastal flooding driven by hurricanes, especially along low-lying areas.  As a result, the damages done by Superstorm Sandy extended another 27 square miles and added over $2 billion in damages.

Warming seas and a wetter atmosphere are supercharging the deluge delivered by tropical cyclones, increasing flood risk.  Five different attribution studies documented the increase in rainfall dumped by Hurricane Harvey due to global warming, with as much as 38 percent as Harvey’s rainfall directly attributable to climate change.

Global warming is also directly driving tropical cyclone activity globally.  The fingerprint of climate change has been documented in tropical cyclone activity in the Northwest Pacific Ocean (e.g. Japan and Philippines) and in the Central Pacific Ocean (e.g Hawaii). In the Atlantic, the U.S. National Climate Assessment reports that human factors have “contributed to the observed increase in hurricane activity since the 1970s.”

As of Monday, September 10, six tropical cyclones (hurricanes/typhoons) have spun up across 4 different ocean basins across the world, including Hurricane Florence which is forecast to make landfall as major (Cat 3 or Cat 4) storm Thursday PM most probably in North Carolina.  As Florence make landfall, it is forecast to slow its forward progress, stalling in place, much like Hurricane Harvey.  For Florence this may lead to rainfall totals approaching two feet, greatly elevating the flood risk. The projected stalling is consistent with a global trend of increasing stalling by tropical cyclones, a trend attributed to the impact of climate change on steering patterns in the jet stream.  North Carolina suffered from devastating floods from a stalled heavy (tropical) storm just a couple years ago.  For more information, see the Climate Signals page on Hurricane Florence which will be updated in real time, documenting how the specifics of the unfolding storm compares to the known signals of climate change.

Accumulated Cyclone Energy in the Northern Hemisphere for the season through September 10 is at its 3rd highest value on record (since 1970): trailing only the 2004 and 2015.

Tweet: One of the clearest and most devastating impacts of climate change has been the dramatic amplification of damage done by hurricanes/tropical cyclones. Run down of the #climatechange science for #Florence here:

Framing Tips for Communication Leads

– Focus on the increasing damages.  Damage is the direct impact your audience sees/experiences.  In addition, that focus sums up all the complicated intermediate impacts of climate change on tropical cyclones.

– Use the present tense.  The impact of climate change on tropical cyclones has already been established. There is no need to talk about how climate change might affect hurricanes in the future.

– Refer to hurricane “activity”.  When discussion the frequency and intensity of hurricanes, refer to the umbrella term “activity” which integrates these two factors, avoiding the complications of discussing the potential trade-offs between the two factors.

– Stick to the script.  Tropical cyclones are complicated and the science on the intersection of cyclones and climate change complicates a complicated topic.  Avoid sloppy language that then necessitates a clarification. Many bad-faith and good-faith commentators actively correct poor advocacy communications, creating unnecessary distraction.