1. Climate Change and Extreme Events: What does this mean for New England?
Ellen M. Douglas, PE, PhD
School for the Environment
University of Massachusetts, Boston
2017 Massachusetts Smart Growth Conference
May 18, 2017

2. Is it hot in here or is it just me?
Theoretically, records will always be broken, but the time between record events should increase.
Climate change is causing just the opposite:
15 of the last 17 years have each been the “warmest year on record”.
April 2016 became the warmest April on record across the planet.
April 2016 crushed the April 2015 record by 0.5 °F
July 2016 was the warmest month on record…EVER!
2016 was the warmest year on record, by a large margin.
NASA: 0.99 ˚C (1.8˚F) above average
NOAA: 0.94 ˚C (1.69˚F) above average
Evidence that human activities are the major cause of recent climate change is even stronger than in prior assessments.

3. Climate change is happening and humans are the predominant cause.
The Intergovernmental Panel on Climate Change (IPCC AR5, 9/27/13):
it is “unequivocal” that Earth’s climate is warming.
Since the 1950’s, it is “extremely likely” that human emission have been the dominant cause of the rise in global temperature.
But how do they know that?
Source: IPCC Climate Change 2007: The Physical Science Basis—Summary for Policymakers.
Evidence that human activities are the major cause of recent climate change is even stronger than in prior assessments.

4. Things don’t appear to be getting better

5. Small changes in an average value can result in larger changes in the extremes.
A changing climate leads to changes in:
Frequency
Intensity
Spatial extent
Duration
Timing
of extreme weather and climate events, and can result in unprecedented extreme weather and climate events.
(IPCC SREX, 2011)

6. Presidentially declared disasters

7. Cost of disasters
Source:

8. Some of these events include…
October 1996: Inland floods (record precip at northeast MA stations)
October 2005: Inland floods southwest NH and northwest MA
May 2006: Inland and coastal floods
April 2007: Inland and coastal floods (2006 & 2007 were “100-yr” floods)
December 2008: Ice storm
February 2010: “Snowicane”
March 2010: 3 weeks of rain & floods (wettest month on record at the Blue Hills Observatory)
August 2011: Hurricane Irene
October 2011: Halloween Blizzard (Snowtober)
Winter and Feb 2012: almost driest on record (darned leap day!!)

9. Some of these events include…
And then there was Superstorm Sandy in Oct 2012…
Sandy was born in a warm and warming tropical Atlantic
Intensified over unusually warm Atlantic waters, then took a rare left turn into New Jersey and NYC.
Record low barometric pressure at center
Record storm surge heights at many locations.
In NYC, Sandy’s max surge hit at astronomically high tide in NYC
In Boston, max surge hit close to low tide.

10. What Sandy looked like in Boston.

11. Long Wharf during Hurricane Sandy
Long Wharf during Hurricane Sandy. This level of flooding actually happens at least once a year, if not more, and it associated with what are called “king tides” – the highest high tides of the year (which also have the lowest low tides). Bostonians call it a “wicked high tide.”
Long Wharf

12. What Sandy COULD have looked like in Boston.

13. School for the Environment, UMass Boston
CLIMATE READY BOSTON Results from Boston Research Advisory Group (BRAG)
Ellen M. Douglas, PE, PhD,
Paul Kirshen, PhD
Robyn Hannigan, PhD
Rebecca Herst
Avery Palardy
School for the Environment, UMass Boston

14. CLIMATE RISK FACTORS Sea Level Rise Coastal Storms Extreme
Precipitation
Extreme Temperatures

15. Emissions Scenarios RCP Scenarios Source: van Vuuren et.al. 2011
Compare RCP and SRES
Source: Cambridge CCVA

16. Hazard: Extreme Temperatures
Consolidated Temperature Projections

20. Hazard: COASTAL STORMS
Background & History
No consensus on changes in tropical or extratropical storm intensity, frequency, or trajectory.
In Boston, tidal range (~10 ft) is typically larger than storm surge
Extratropical storms are more common, have longer durations, and follow tracks more favorable for flooding, currently produce most storm-induced flooding events in the Boston metro region.
Projections
Large uncertainties in the response of future storm characteristics to human-induced climate change.
Extra-tropical storm surge CDF based on residual high water levels at Boston.
(Source: Figure 4-25 in Bosma et al., 2015)

21. HAZARD: SEA LEVEL RISE

22. Hazard: COASTAL FLOODING
Consolidated flooding PROJECTIONS

23. King Tide, October 18, 2016

24. Things we know about climate change
Human greenhouse gas (GHG) emissions are the main cause of the warming that we’ve observed since 1880.
Our emissions history has embedded change into the climate system (we need to adapt).
Reducing GHG emissions now will reduce impacts later in the century (we need to mitigate).
Climate change is not just a coastal issue, but an everywhere issue.
If we ignore the changing climate, our future plans and designs will be wrong.
Evidence that human activities are the major cause of recent climate change is even stronger than in prior assessments.

25. Thank YOU!
Evidence that human activities are the major cause of recent climate change is even stronger than in prior assessments.