understanding our climate crisis

Understanding Our Understanding Our

CLIMATE CRISISCLIMATE CRISIS

Session 2 How do Higher Session 2 How do Higher Temperatures Impact Temperatures Impact

Creation?Creation?Dr. Henry Brouwer

Meadowlands Fellowship Christian Reformed ChurchSeptember 22, 2019

CO2 increasing

about 2 ppm/yearCO2 is increasing between 2-3 ppm per year

Impacts of a Warming Earth

1. Changes in weather patterns

2. Melting of Glaciers and ice fields

3. More intense storms and rainfall

4. Higher death rates

5. Loss of species

6. Wildfires

7. Food production

Changes in Weather Patterns

Difference between weather and climate– Weather – what we experience daily

– Climate – long term trends

Future climate - more violent storms and heavier precipitation in some areas, drought in others

Why? Warmer air leads to stronger convection currents (winds)

Due to differences in density between warmer and cooler air

Rate of evaporation of water from equatorial oceans increases

Also changes density of air – how?

Effect of Water Vapour on Air DensityA bit of chemistry. Water (H

2O) consists

of 2 H atoms and 1 O atom. Each O atom is 16 times as heavy as a H atom. We say that the molecular mass of water is (2 x 1 + 1 x 16) = 18 units. Oxygen gas is O

2

and hence its mass is (2 x 16) = 32 units. Similarly, nitrogen gas is N

2 and its mass

is (2 x 14) = 28 units.

One of the basic laws in Chemistry is known as Avogadro's Principle: “Equal volumes of any gas contain the same number of molecules at the same T and P” Thus, when there is more water vapour in the air, some of the oxygen

and nitrogen molecules get displaced and the air becomes LESS dense. Thus, warm and moist air will create stronger

convection currents (winds).

Hurricane Season 2017

Harvey Aug. 17, Category 4

Irma Aug. 30, Category 5

Maria Sept. 16, Category 5

First recorded Category 5 hurricanes in the Atlantic

Estimated damage (Bloomberg Business)– Over $200 Billion

Hurricane Florence(observed from ISS Sept. 12, 2018)

Images of Florence Flooding 2018

Cyclones 2019

Idai - March 2019

● Worst tropical storm to hit Southern Africa● Affected Mozambique, Zimbabwe, and Malawi● 1000+ people killed● >$2 Billion in damage

Fani - early May

● India and Bangladesh● Early warnings allowed people in path of cyclone to

move to higher ground – few deaths

India floods: At least 157 dead and hundreds of thousands evacuated as monsoon lashes region (Aug 12, 2019)

An aerial view shows a flooded residential area after heavy rains in Ahmedabad, India on 10 August 2019. ( REUTERS )

What causes the extreme flooding associated with hurricanes?

More precipitation

– Warmer air is capable of holding more water vapour

• For each oC rise, air can hold about 7% more water vapour

– Will transfer more water from oceans to land

– Results in severe flooding, landslides, erosion

Precipitation not predictable

– Due to changes in wind and temperature patterns around the world, some areas will experience much more precipitation, while others drought

– Monsoons no longer predictable

• Serious impact on agriculture

Changing Monsoon Seasons

“Irregular monsoon has become the new norm for India,” Roxy Mathew Koll, a climate scientist at the Indian Institute of Tropical Meteorology, told The Independent.

“This year, the monsoon was severely deficit (35 per cent) during June, which was followed by heavy rain events in July and August.

“This is an emerging pattern for India's monsoon: increasing droughts intermittent with heavy rainfall events.”

Mr Koll said that extreme rainfall events in India have tripled between 1950 and 2018, with many resulting in devastating floods. He put the damages at about US $3 billion (£2.5bn) per year.

https://www.independent.co.uk/news/world/asia/india-floods-death-toll-latest-kerala-karnataka-monsoon-climate-change-a9054586.html

Hu

Hurricane DorianAug. 24 – Sep. 9 2019

Category 5

Storm SurgeCauses

– Strong winds push water

– Low pressure causes water to rise

Result: serious coastal flooding

Presentation by World Renew

Effects on Oceans

About 90% of heat energy is absorbed by oceans Rising ocean levels – two main reasons:

1. Melting of land-based glaciers will add to total amount of water ending up in the oceans e.g. Greenland, Antarctic, Himalayas, Rockies• Melting icebergs or sea ice will not affect water level

2. Warming of water causes it to expand - leads to a significant rise in water level (average depth of ocean about 3.5 km)

• A 1oC rise in ocean temperature causes an expansion of about 75 cm (assuming uniform temperature)

Will impact especially low lying countries and coastal cities

High Tides Flooding in Miamiresulting from sea-level rise

Sea Level Rise since 1993

Effect on Ocean Acidity (pH)● Carbon dioxide is an acidic gas

– Forms carbonic acid in water

– Lowers pH (slightly less basic)

Impact of pH change on ocean creatures

https://coastadapt.com.au/ocean-acidification-and-its-effects

Photo (1) shows healthy coral. It's then seen bleached (2). Photo (3) shows dead coral with a film of algae, which grows thicker in photo (4).

Glaciers 68% of earth's freshwater found in glaciers and icecaps Glaciers moderate temperature

Melting of glaciers absorbs tremendous amount of heat energy Helps to prevent rapid rise in earth's temperature

Presence of ice cover reflects most of solar energy back into space

About 90% of glaciers worldwide retreating Glaciers serve as water storage for the world

Melting of glaciers provides water in the summer

What happens if they melt too fast? Will affect the water supply in the Prairies and Vancouver Asia depends on glacial meltwater from the Himalayas Glaciers on Kilimanjaro almost extinct

Pedersen Glacier Alaska

Athabasca Glacier

One of the most accessible glaciers and visited by thousands every year

– Has retreated about 2 km since 1844

– Meltwater is the source of the Athabasca River

– Flows through Alberta tar sands to Lake Athabasca and eventually to the Arctic Ocean via the Mackenzie River

Loss of Ice Cover

Changes in the ArcticArctic sea ice melting

– More energy absorbed by open water• Ice or snow cover reflects solar radiation, while open water

absorbs it

– Ice also covered with 'soot' – absorbs sun's energy

– Leads to higher temperatures in Arctic• Increasing about twice as fast as rest of world

– Thawing of permafrost• Instability of housing, roads, shorelines

• Release of methane gas from decay of organic matter

• Destabilization of methane hydrates found in the Arctic Ocean

– Affects indigenous communities in Arctic

The extreme melting on 1 August liquified enough ice to fill 5 million Olympic-sized swimming pools with water, accounting for 12.5 gigatons of water.

https://eos.org/articles/greenland-ice-sheet-beats-all-time-1-day-melt-record

Changes in average temperatures between 2014 and 2018

https://interestingengineering.com/nasa-2018-4th-hottest-year-on-record-arctic-warming-faster

WildfiresFort McMurray May 1 to July 5, 2016

– Estimated damage cost of C$9.9 billion

– Costliest disaster in Canadian history

– Burned about 1.5 million acres

– 88,000 people evacuated

Wildfires in BC

Mountain Pine Beetle

– Native to southern BC

– Normally populations low

– Warmer winters allows beetle to survive and move north

– Infestation overwhelms natural tree defenses

– Serious fires result

https://www150.statcan.gc.ca/n1/pub/16-508-x/16-508-x2019002-eng.htm

Fires in the Amazon

Region 2019

165,000 in Amazon

70,000 in Brazil

https://www.cbc.ca/news/technology/amazon-fires-brazil-1.5256135