Climate Variability and Change: Introduction to Course

1. Climate Variability and Change: Introduction to Course

2. Climate Variability and Change: Introduction to Course Observed long-term trends: manmade or natural?

3. Climate Variability and Change: Introduction to Course The coupled climate system has important natural variability

4. Climate Variability and Change: Introduction Temperature anomalies for July 2010

5. Climate Variability and Change: Introduction

6. Climate Variability and Change: Introduction

7. Climate Variability and Change: Introduction

8. Climate Variability and Change: Introduction What are the causes of the observed anomalies?

9. Climate Variability and Change: Introduction Can we predict these anomalies a season ahead?

10. Climate Variability and Change: Introduction Was the hot July in Western Europe part of a global warming signal?

11. Climate Variability and Change: Introduction Was the hot July in Western Europe part of a global warming signal caused by us?

12. Climate Variability and Change: Introduction The global average temperature for July 2013 was 0.61oC above the 20th Century average. Is this a global warming signal?

13. Climate Variability and Change: Introduction Global Highlights The combined average temperature over global land and ocean surfaces for July 2013 was the sixth highest on record, at 0.61°C (1.10°F) above the 20th century average of 15.8°C (60.4°F). The global land surface temperature was 0.78°C (1.40°F) above the 20th century average of 14.3°C (57.8°F), marking the eighth warmest July on record. For the ocean, the July global sea surface temperature was 0.54°C (0.97°F) above the 20th century average of 16.4°C (61.5°F), the fifth warmest July on record. The combined global land and ocean average surface temperature for the January–July period (year-to-date) was 0.59°C (1.06°F) above the 20th century average of 13.8°C (56.9°F), tying with 2003 as the sixth warmest such period on record.

14. Climate Variability and Change: Introduction

15. Climate Variability and Change: Introduction July 2013 was a warm one in the Northeast. Eleven of the twelve Northeast states ranked this July among their top 20 warmest with Rhode Island and Massachusetts having their warmest July on record. Twenty-six of the thirty-five first order sites ranked this July among their top 20 warmest, with three sites setting monthly temperature records.

16. Climate Variability and Change Affects Society Climate impacts: food and water health infrastructure and transport demography energy

18. The Sahel (15-20N)

19. The Sahel experienced one of the most dramatic decadal signals last century

20. Climate Variability and Change Affects Society in the US Climate impacts: food and water health infrastructure and transport demography energy

21. Climate Variability and Change Affects Society in the US Bonnie (05) Charlie (05) Frances (05) Flooding in New Orleans due to Katrina (courtesy NOAA) Ivan (05) courtesy A. Aiyyer

22. Climate Variability and Change Affects Society in the US

23. Science and Society Interact Society demands useful predictions of climate so that it can respond to climate variability. One key question to ask is: What do the users of these forecasts need? In recent years most seasonal predictions have been concerned with providing the mean seasonal rainfall anomaly – not always useful. Users tend to want more than this – when will the rainy season start? How will the rainfall be distributed within the season (weather?)? These are much harder to predict.

24. Limits of predictability weather – theoretically 1-2 weeks – TOPS!; currently much less than this, probably around 5 days or so – limitations include poor models and poor observations of the atmosphere especially. climate – forecasts are made at seasonal-to-interannual and multi-decadal timescales (including climate change) – limitations include poor models, poor observations of “climate system” – includes land and ocean , less important for weather.

25. Seasonal-to-Interannual variability • We will discuss the basis for these forecasts in this course. • Need to understand causes of seaonal-to-interannual variability. At these timescales it is crucial to provide information on the status of ENSO and to be able to predict the impacts of ENSO locally and around the globe (teleconnections).

26. Multidecadal Fluctuations and Trends • Efforts are also made to make predictions on longer timescales

27. Introduction to the course

28. Section 1: Introduction to the Climate System Provides background to the mean climate system, combines observations of key variables of the climate system and a physical understanding of key processes. These sections are required for a basic understanding of the climate system and processes before we can attempt to consider its variability. Many textbooks exist that cover these areas.

29. Section 2 Natural Climate Variability We will consider the nature of observed seasonal-to-interannual variability – (things we wish to predict) - Most importantly in this section is ENSO (observations, mechanisms and impacts (teleconnections). In addition we will discuss decadal variability – important to be aware of this when attempting to attribute anomalies to a “global warming” trend. We will discuss how climate predictions are made Finally we will consider how climate variability is manifested in changes in high impact weather.

30. Section 3 Climate Change We will consider the theory of climate change We will look at the observational evidence as well as how climate predictions are consistent (or not) with this. The IPCC process will be discussed

31. Section 4 Future Perspectives We will finish with some discussion on how science and society are interacting with regards to climate variability and change.

32. Section 4 Future Perspectives

33. Section 4 Future Perspectives

34. Section 4 Future Perspectives What can we do?

35. ‘We basically have three choices: mitigation,adaptation and suffering. We’re going to do some of each. The question is what the mix is going to be. The more mitigation we do, the less adaptation will be required and the less suffering there will be.’ John Holdren,Former President, American Association for the Advancement of Science now Director of the White House Office of Science and Technology Policy(OSTP)

36. We need a new generation of young scientists to solveour future energy problems – education is key!

37. Final 5 questions equally approximately equally weighted: 3 questions on Natural Variability AMO ENSO Prediction Weather versus Climate 2 questions on Climate Change Theory of climate change Modeling – past and future

38. Other Climate-Related Courses Spring 2014 ATM405 Water and Climate Change ATM413 Weather, Climate Change and Societal Impacts ENV480 Climate Modeling Fall 2014 ATM404 Oceans and Climate

39. SIRFs • Please fill out SIRF evaluations • In comments please can you address waiting of Natural versus Climate Change content. • Also – anything you would have liked to have seen? • Anything you didn’t like so much?