Brooks Range, AK

Global measurements of atmospheric gases and aerosolsAmazon Basin, 2008 -- 2009Arctic Ocean measurements, 2009 -- 2011

Steven C. Wofsyand the Science Team of theBARCA Program and the HIAPER Pole-to-Pole Observations Program

Global environmental changes—in the “natural” environment and the built environment—represent some of the most powerful forces that give rise to “extreme” or “sudden” events.

This lecture discusses changes in the chemical composition of the atmosphere – what we know about the past, and the present changes that are unfolding.

The temperature of the earth has increased by 0.8 C since 1920 http://data.giss.nasa.gov/gistemp/graphs/

The heavier temperature lines from 160,000 BP to present reflect more data points for this time period, not necessarily greater temperature variability.

Climate and Atmospheric History of the past 420,000 years from the Vostok Ice Core, Antarctica , by Petit J.R., Jouzel J., Raynaud D., Barkov N.I., Barnola J.M., Basile I., Bender M., Chappellaz J., Davis J. Delaygue G., Delmotte M. Kotlyakov V.M., Legrand M., Lipenkov V.M., Lorius C., Pépin L., Ritz C., Saltzman E., Stievenard M., Nature, 3 June 1999.

Paleoclimate data from Antarctic Ice Cores

Changes in atmospheric composition: “Greenhouse gases”, CO2

Time from present 1000’s of years

CO

2 c

hang

e fr

om t

he p

rese

nt,

ppm

How are people changing the global environment?

Atmospheric methaneAt

mos

pher

ic M

etha

ne C

once

ntra

tion

(par

ts p

er b

illio

n)

500

100

0

1500

Atm

osph

eric

Met

hane

Con

cent

ratio

n

500

100

0

1500

-150,000 -100,000 -50,000 0 -4000 -3000 -2000 -1000 0 Time before present (Years) Time before present (Years)

Intergovernmental Panel on Climate Change – IPCC

Insert a news item showing that increasing numbers of the public think "Climate Change" is a hoax, or too uncertain to inform policy, etc.

Some questions about the global environment:Q1. How quickly is the earth warming, and what are the consequences ? (Not required to ask, and answer this question: perfect knowledge of how much warming might be attributed to human activities.)Q2. Is aridity (dryness; Precipitation – Evaporation) increasing in vulnerable places?Q3. What climate changes are ongoing in the Arctic; what is the response of sea level, and of “greenhouse” gases (CO2, CH4)?

Examples of recent studies of the Arctic environment

Changes in Sea Level are linked to climate through the temperature of the ocean and the stranded ice on the continents

Rate of Ice volume change:

All Greenland: -238 km3/yr

South Greenland: -164

North Greenland: -65

73.250 N

-238 km3/yr = 0.5 mm/yr sea level rise

1979

2007

The Arctic Ocean has been covered by floating ice for all human history……until

What do these changes mean for climate, forests, crops?

1. Arctic

GV launch in the rain, Anchorage, January, 2009 (HIPPO-1)

HIPPO platform: NCAR Gulfstream V "HIAPER"

41+ kft

28 kft

Flight Plan across the arctic ocean 60N to 82N, August 2011

Photos: S. Wofsy

August, 2011

UT NN GGLAT GGLON ALT m To C74520 1467 75.04469 -161.5916 653.708 -4.736278

UT NN GGLAT GGLON ALT m To C 74580 1469 75.11114 -161.5076 403.508 -3.894623

UT NN GGLAT GGLON ALT m To C74640 1473 75.17651 -161.4241 257.740 -3.14

UT NN GGLAT GGLON ALT m To C77280 1481 78.70973 -156.4544 3854.904 -25.08

Photos from 19 Aug 2011

Photos: S. Wofsy

Mist rising from very warm water 200km in the ocean

CH4 in the arctic atmosphere

GLOBAL METHANE SOURCES, Tg a-1 [IPCC, 2007]

ANIMALS80-90

LANDFILLS40-70

GAS50-70

COAL30-50RICE

30-110

TERMITES20-30

WETLANDS100-230

BIOMASSBURNING10-90

Sink: oxidation by OH (lifetime of 10 years)

CH4

HIPPO

Methane is being produced in the surface waters of the Arctic Ocean, especially where the ice pack has broken up, and we see this new emission in the atmosphere.

Slide from: E. A. Kort

Relationships between tracers with distinct sources: A tool for understanding large scale sources and sinks of GHGs.

82N 15 April 2010

CO2

78N 02 Nov. 2009

385 386 387 ppm

1880

189

0 1

900

CH

4

CH4:CO2 = .0085

Photos: by; B. C. Daube & J. V. Pittman

Summary: The Arctic

The data show:

•Dense pollution at both very high altitudes, and at low levels, in the Arctic.

•Sources of CH4 in the Arctic from from the ocean surface, significant compared to fossil fuel extraction and land surface.

•Extensive loss of floating ice in the Arctic Ocean, and melting of glacial ice on Greenland.

… and a lot more

Summary: Environmental Science and Engineering, Global Change element

What people in this field are doing:

• Making measurements in the atmosphere, in the sea, on land, and in the ecosystems of land an sea.

•Creating databases that can be accessed widely, and constructing models to simulate natural systems.

• Analyzing and modeling these observations to address questions important to science, and to society.

… and a lot more