extreme rainfall events and climate change

32

Click here to load reader

Upload: t-ramachandran

Post on 12-Apr-2017

219 views

Category:

Environment


0 download

TRANSCRIPT

Page 1: Extreme Rainfall Events and Climate Change

T. R. Ramachandran

23 January 2016

Extreme Rainfall

Presented during “Chennai’s Legacy: A conversation on governance, environment and society following the 2015 floods”

Page 2: Extreme Rainfall Events and Climate Change

“Freak Weather”

“Perfect Storm”

Page 3: Extreme Rainfall Events and Climate Change

3

The highest daily rainfall in a century. Freak weather conditions on one day. The hottest-ever Indian Ocean. The strongest-ever El Niño. The hottest year on record. The bad news is that a perfect storm of meteorological conditions combined to create Chennai’s worst-ever deluge last week, exacerbated in no small part by civic infrastructure pushed to its limit and systemic dysfunction

Page 4: Extreme Rainfall Events and Climate Change

A Question

Page 5: Extreme Rainfall Events and Climate Change

How Many States in the US had Monthly Record-Breaking Rainfall in 2015?

5

Page 6: Extreme Rainfall Events and Climate Change

2015: Record Monthly Rainfall in US # State Town/City Record Broken in Highest In ~

1 North Carolina Charlotte Nov 137 years

2 Texas Dallas/Fort-Worth & others +

State May, Nov, Full Yr 117 years

3 Oklahoma Oklahoma City + State May, Nov 120 years

4 New Jersey Millville Jun 120 years

5 Illinois State Jun 120 years

6 Missouri St. Louis, Springfield + State Jun, Nov, Dec, Full Yr 141 years

7 South Carolina Charleston + other towns Oct 125 years

8 Maryland Baltimore Jun 142 years

9 Minnesota Many towns May 130 years

10 Iowa Sioux City Nov 100 years

11 California Los Angeles, San Diego Jul 138 years

12 Colorado Boulder, Col. Springs + State Feb, May 121 years

6

Page 7: Extreme Rainfall Events and Climate Change

2015: Record Monthly Rainfall in US # State Town/City Record Broken in Highest In ~

13 Nebraska Lincoln May 100 years

14 Arkansas Fort Smith + others May, Dec, Full Yr 133 years

15 Vermont Montpelier, Mt. Mansfield Jun 120 years

16 Ohio Several towns Jun 120 years

17 Hawaii Honolulu August 138 years

18 Massachusetts Boston, Worcester Feb, Winter 142 years

19 Indiana Fort Wayne + State Jun 120 years

20 Oregon Portland Dec 75 years

21 Florida Miami-Dade Dec 83 years

- Contiguous US Entire country May 121 years

7

Source: http://www.kanvz.com/trr/canvas/1444143085761

Page 8: Extreme Rainfall Events and Climate Change

2015: Record Monthly Rainfall in US # State Town/City Record Broken in Highest In ~

1 North Carolina Charlotte Nov 137 years

2 Texas Dallas/Fort-Worth & others +

State May, Nov, Full Yr 117 years

3 Oklahoma Oklahoma City + State May, Nov 120 years

4 New Jersey Millville Jun 120 years

5 Illinois State Jun 120 years

6 Missouri St. Louis, Springfield + State Jun, Nov, Dec, Full Yr 141 years

7 South Carolina Charleston + other towns Oct 125 years

8 Maryland Baltimore Jun 142 years

9 Minnesota Many towns May 130 years

10 Iowa Sioux City Nov 100 years

11 California Los Angeles, San Diego Jul 138 years

12 Colorado Boulder, Col. Springs + State Feb, May 121 years

8

Eliminated extreme drought of past 5 years 35T gallons, ~27 yrs drinking water for world

Eliminated extreme drought of past 5 years

Across NJ, 4th wettest Jun after 3rd driest May

Eliminated drought in several parts of state

Wettest months usually Jan-Mar, more rain in 1 day in Jul than all of Jan after worst drought in > a century

Wettest month usually Mar

Wettest months usually Sep-Nov

Wettest month usually Jun

Wettest months usually Aug-Sep

Wettest month usually May

Wettest months usually Jul-Aug

Sixth “1-in-1000 year” event since 2010

Page 9: Extreme Rainfall Events and Climate Change

Should We Keep Assuming These Are Just “Freak” Events?

Page 11: Extreme Rainfall Events and Climate Change

Extreme Rainfall Events in the US

11

Source

nca2014.globalchange.gov

Page 12: Extreme Rainfall Events and Climate Change

A Key Factor

12

Page 14: Extreme Rainfall Events and Climate Change

Averages are Misleading - I

14

Page 15: Extreme Rainfall Events and Climate Change

Increasing Likelihood of Extreme Events

15

Page 16: Extreme Rainfall Events and Climate Change

Averages are Misleading - II

16

Page 18: Extreme Rainfall Events and Climate Change

Local T Anomalies

18

Page 19: Extreme Rainfall Events and Climate Change

Averages are Misleading - III

19

Page 20: Extreme Rainfall Events and Climate Change

Here’s What is Happening in the Oceans – That Cover 70% of Earth’s Surface

20

Source

The Vast Majority of Warming is Actually Occurring in Our Oceans

Page 21: Extreme Rainfall Events and Climate Change

Staggering Level of Ocean Warming Has Widespread Consequences

21

Source

The Heat Trapped in Our Oceans Since Recorded History Has Doubled Since 1997

How Much Heat?

Page 22: Extreme Rainfall Events and Climate Change

What is Causing Global Warming?

Page 23: Extreme Rainfall Events and Climate Change

Predominantly CO2 (with some CH4)

23

Source

Page 24: Extreme Rainfall Events and Climate Change

We’ve Changed Our Atmosphere Radically Since the Industrial Revolution

24

Source

Page 25: Extreme Rainfall Events and Climate Change

But Isn’t El Nino The Cause of Anomalous Warming?

Page 28: Extreme Rainfall Events and Climate Change

In Short

Less “Freak”, Less “Perfect Storm”

More “Climate Change”

Page 29: Extreme Rainfall Events and Climate Change

So, Where is the Excess CO2 Coming From?

Page 31: Extreme Rainfall Events and Climate Change

What We Need to Do

Page 32: Extreme Rainfall Events and Climate Change

Takeaways 1. Focus more aggressively on switching from coal, oil,

gas to solar, wind, hydro (and if needed, nuclear) Collective effort required, driven by government

Balance needs of development with needs of survival and livelihoods

2. Make the soil around our homes and buildings strongly water-absorbent – esp. in towns and cities The right soil, the right vegetation, the right trees for the location

Allows water to seep through and get distributed slowly to water respositories

Ideally, do not build near large water bodies or low lying areas

3. Listen to experts when it comes to making and enforcing laws that impact the world around us Tap into wealth of research and learning worldwide

32