Download NOAA 31st Climate Diagnostics and Prediction Workshop Boulder, Colorado October 25 2006

Challenges in Attribution of Climate Variability and Trends
NOAA 31st Climate Diagnostics and Prediction Workshop
Boulder, Colorado
October 25 2006
Popular Views On Attribution
Popular Views On Attribution
Popular Views On Attribution
What is Attribution?
•Attribution is the action of ascribing a known condition to a particular source or sources.
•Attribution is the process of establishing cause and effect.
•Attribution science involves the comprehensive explanation of current and evolving
climate conditions…both variability and change,
•Attribution seeks to explain the role of forcings…both natural and anthropogenic.
•Attribution includes the explanation of climate predictions…their success and failure.
Why is Attribution Important?
Why is Attribution Important?
In Spring 2006, the Senate Commerce
Disaster Prevention and Prediction Subcommittee
requested NOAA to explain the very warm and
evolving drought conditions in the West.
Why is Attribution Important?
Why is Attribution Important?
Why is Attribution Important?
Why is Attribution Important?
US House Committee on Science
met 7 October 2005 to have NOAA
explain its prediction of hurricanes.
Current Attribution Challenges
• Why has there been a recent increase in Atlantic hurricane activity?
Current Attribution Challenges
• Why has there been a recent increase in Atlantic hurricane activity?
Current Attribution Challenges
• How do we explain the 2006 hurricane predictions?
Current Attribution Challenges
• How do we explain the 2006 hurricane predictions?
Predictions of tropical activity in the 2006 season
Source
Date
Named storms
CSU
Average (1950–0)
NOAA
Average
Record high activity
Record low activity
CSU
CSU
NOAA
CSU
CSU
NOAA
CSU
CSU
5 December 2005
4 April 2006
22 May 2006
31 May 2006
3 August 2006
8 August 2006
1 September 2006
3 October 2006
Activity to date
9.6
10
28
4
Hurricanes Major hurricanes
5.9
6
15
2
2.3
2
8
0
17
17
13–16
17
15
12–15
13
11
9
9
8–10
9
7
7–9
5
6
5
5
4–6
5
3
3–4
2
2
9
5
2
Current Attribution Challenges
• How do we explain the regionality and the seasonality of US sfcT trends ?
Current Attribution Challenges
• How do we explain the regionality and the seasonality of US sfcT trends ?
Current Attribution Challenges
• How do we explain the regionality and the seasonality of US sfcT trends ?
Current Attribution Challenges
•
How do we explain the long-lead seasonal outlooks?
Current Attribution Challenges
•
How do we explain the long-lead seasonal outlooks?
Current Attribution Challenges
• Is the risk of drought now increasing, and if so, why?
Drought Statistics: 1895-1950
Areal-Coverage of PDSI<-3
Average Duration of PDSI<-3
Drought Statistics: 1951-2005
Areal-Coverage of PDSI<-3
Average Duration of PDSI<-3
• Explaining Changes in Extreme US Climate Events…….Jerry Meehl
• Explaining US Precipitation and Temperature Trends….Imke Durre
• Explaining Origins of North American Drought………….Richard Seager
• Explaining Increases in Atlantic Hurricane Activity……Kevin Trenberth
Overarching Challenge:
Given the public perception of climate change and an increase in extreme events
(e.g. droughts, heat waves, hurricanes), how well is our science community positioned
to provide critical decision support information (e.g., answer to the questions
what happened, why it happened, and what is likely to happen next)
needed for planners to make decisions and manage risk?
Overarching Challenge:
Given the public perception of climate change and an increase in extreme events
(e.g. droughts, heat waves, hurricanes), how well is our science community positioned
to provide critical decision support information (e.g., answer to the questions
what happened, why it happened, and what is likely to happen next)
needed for planners to make decisions and manage risk?
Q1
What attribution questions are of high relevance to decision makers,
e.g., in water resources planning, agriculture, energy, and policy making
for sustainable development?
Overarching Challenge:
Given the public perception of climate change and an increase in extreme events
(e.g. droughts, heat waves, hurricanes), how well is our science community positioned
to provide critical decision support information (e.g., answer to the questions
what happened, why it happened, and what is likely to happen next)
needed for planners to make decisions and manage risk?
Q2
What is the contribution of natural variability
to the U.S. warming since 1970s?
Overarching Challenge:
Given the public perception of climate change and an increase in extreme events
(e.g. droughts, heat waves, hurricanes), how well is our science community positioned
to provide critical decision support information (e.g., answer to the questions
what happened, why it happened, and what is likely to happen next)
needed for planners to make decisions and manage risk?
Q3 What is the explanation for regionality and seasonality of US temperature
trends since the 1970s?
Overarching Challenge:
Given the public perception of climate change and an increase in extreme events
(e.g. droughts, heat waves, hurricanes), how well is our science community positioned
to provide critical decision support information (e.g., answer to the questions
what happened, why it happened, and what is likely to happen next)
needed for planners to make decisions and manage risk?
Q4 What is the documented evidence for trends in climate extremes over the US?
Overarching Challenge:
Given the public perception of climate change and an increase in extreme events
(e.g. droughts, heat waves, hurricanes), how well is our science community positioned
to provide critical decision support information (e.g., answer to the questions
what happened, why it happened, and what is likely to happen next)
needed for planners to make decisions and manage risk?
Q5 How do we explain the successes and failures of individual climate forecasts?
Overarching Challenge:
Given the public perception of climate change and an increase in extreme events
(e.g. droughts, heat waves, hurricanes), how well is our science community positioned
to provide critical decision support information (e.g., answer to the questions
what happened, why it happened, and what is likely to happen next)
needed for planners to make decisions and manage risk?
Q5 What is the reason for the controversy in explaining Atlantic Hurricane
variability?