Climate change and disaster risk management -- Is the changing climate affecting disaster risk?

Workshop on Disaster Risk Management and Climate Change Adaptation Washington DC, September 2010

Climate change and disaster risk management

--Is the changing climate affecting disaster risk?

Ian NobleENV Climate Change Team


Bulletin of the American Meteorological Society 2010 doi: 10.1175/2010BAMS3092.1

Have disaster losses increased due to anthropogenic climate change?

Laurens M. BouwerInstitute for Environmental Studies, Vrije Universiteit, Amsterdam, The Netherlands


BBC Summary -- “…according to scientists, up until now, weather-related natural hazards, with their inherent variability, may have not been increasing – it’s the vulnerability of the population that has seen a sharp rise.”

NHPR -- The paper “… finds no causal link between increases in disaster losses and man-made climate change.”

Study Finds No Link Tying Disaster Losses to Human-Driven WarmingBy ANDREW C. REVKIN NYT

http://dotearth.blogs.nytimes.com/author/andrew-c-revkin/


Conclusions• The analysis of twenty-two disaster loss studies shows that

economic losses from various weather related natural hazards, such as storms, tropical cyclones, floods, and small-scale weather events such as wildfires and hailstorms, have increased around the globe.

• The studies show no trends in losses, corrected for changes (increases) in population and capital at risk, that could be attributed to anthropogenic climate change.

• Therefore it can be concluded that anthropogenic climate change so far has not had a significant impact on losses from natural disasters.

• Considerable uncertainties remain in some of these studies, as exposure and vulnerability that influence risk can only be roughly accounted for over time.

• In particular the potential effects of past risk reduction efforts on the loss increase are often ignored, because data that can be used to correct for these effects is not available.

“The bottom line? Regardless of what happens due to global warming, on a crowding, urbanizing planet, increased exposure to, and losses from, nature’s hard knocks are a sure thing if people keep settling in harm’s way.” Andrew Revkin


What have we observed?


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1972 1977 1982 1987 1992 1997 2002

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LICL-MICU-MICDeveloped

More and more people are being affected by climate related disasters each decade


We believe that the increase seen in the graph until about 1995 is explained • partly by better reporting of

disasters in general, • partly due to active data

collection efforts by CRED and • partly due to real increases

in certain types of disasters.

We estimate that the data in the most recent decade present the least bias and reflect a real change in numbers. This is especially true for floods and cyclones. Whether this is due to climate change or not, we are unable to say.

CRED (Centre for Research on the Epidemiology of Disasters)


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1972 1977 1982 1987 1992 1997 2002

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LICL-MICU-MICDeveloped

More and more people are being affected by climate related disasters each decade


1975 1980 1985 1990 1995 2000 20050

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LDCMICUMICHIC

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ts p

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1975 1980 1985 1990 1995 2000 20050

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DroughtFloodStormTemp Extr

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1975 1980 1985 1990 1995 2000 2005 20100.0

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f(x) = 38622.1538621585 x − 75638363.4609224R² = 0.440109284679355

People affected per flood event


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1880 1900 1920 1940 1960 1980 2000 2020

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Unusually low number of physical disasters in early 1960s & 1970s

Unusually high number of climate disasters in early

2000s

Climate related disasters are increasing faster than non-climate disasters


-14 -12 -10 -8 -6 -4 -2 0-20%

-10%

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CPIA 2005 Improving --->

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LDCs – governance seems to matterPercent change in people affected per 5 years

Area of dot represents number of people affected


What can we learn from climate modelling?

Increase annual max number consecutive dry days (<1 mm) Kamaguchi SOLA 2006

Blue – Cooler conditions (-3 to 19 °C)Pink – Mild conditions (19 to 29 °C)Red – Hot conditions (29 to 35 °C)

Warmer conditions more moisture in air heavier ppt events

Fraction of annual rainfall falling in extreme events (>95% of current)

Changes in flood frequency

1 In 100 year flood returns every 20 years1 in 20 year flood returns every 6 years

100-drought frequency 2020Lenher et al 2006 Climatic Change

Cyclone intensityWebster et al 2005 Science 309, 1844

• Noda et al Earth Simulator from Oouchi et al 2005

• Cyclone frequency at end of 21st C

• Overall frequency will fall but number of intense events will increase

But don’t expect much detail on cyclone paths

In a 4 °C scenario, most land surface temperature increases will be well above 4 °C


It is not all about extremes and disasters.

Imagine living through summer after summer in an ‘Oslo’ designed house relocated to central Spain


Takeshi Enomoto, Earth Simulator Center/JAMTEC Cloud representation at 320 km grid (Left) versus 20 km (Right) for the same point in a model run

Seasonal forecasting - NOAA

• 1, 3 & 5.5 month precipitation forecast

• But essentially little useable information beyond 1 month

Which “Early Warning Systems”

are feasible?

Climate change and disaster risk management -- Is the changing climate affecting disaster risk?

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