CLIMATE CHANGE & POPULATION

Ian Lowe

GEO4: “Unprecedented environmentalchange at global and regional levels”

• Increasing global average temperatures, widespread melting of snow and ice, rising global average sea level

• Unsustainable land use and climate change driving land degradation

• Aquatic ecosystems heavily exploited• Water availability declining globally

• Almost all well-studied species declining in distribution, abundance or both

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Earth is overheating

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Earth is overheating

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Global warming is affecting Australia today

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Global Temperature Change

1980s: warmest decade ever

1990s: even warmer. Every year above 1980s average

2000s: warmer yet. Every year above 1990s average.

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To have a better than even chance of keeping global average temperature rise below 2°C, the world would need to be emitting less than half the 2000 amount of CO2 by 2050.

So global emissions need to peak by 2020 and then decline rapidly.

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IPCC AR5 Synthesis Report

The window for action is rapidly closing

65% of our carbon budget compatible with a 2°C goal already used

Amount Used1870-2011:

515GtC

Amount Remaining:

275GtC

Total Carbon Budget:

790GtC

AR5 WGI SPM

‘Cumulative emissions of carbon dioxide largely determine global mean surface warming by the late 21st century and beyond’

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0

200

400

600

800

1000

1200

1990 2000 2010 2020 2030 2040 2050

Energy Transport Fugitive, waste and industrial processes)Agriculture Land clearing

Kyoto target

60 - 90% reductions

Business As Usual

Source: Adapted from the Australian Greenhouse Gas Inventory and ABARE projections

Australia’s Emissions (Mt)Where we

are going

What we need to achieve

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Current strategy• Billions for public subsidies of fossil

fuel use [car production & use, aviation, road freight, aluminium…]

• Export of fossil fuels on huge scale [with further expansion plans]

• Large costs of climate change [drought, cyclones, bushfires, water…]

• Little serious spending on solutions • superficial talk of nuclear power or

“clean coal”

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IEA World Energy Outlook 2008

“nothing short of an energy revolution”

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Sustainable energy future

• Improve efficiency of turning energy into services [transport, cooling, lighting, motive power etc]

• Phase out supply technologies based on problematic resources

• Eliminate technologies imposing unacceptable environmental costs

Overseas trends

• Solar is now the cheapest power in the USA: 3.87 c / kWh

• Renewables half of all new power installed globally in 2014

• ~ 30% power now from renewables

• Gas replacing coal

• Total coal use declining

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Cost of new power(Bloomberg New Energy Finance 7/15)

• Wind farm $74 / MWh

• Baseload gas 92

• Large scale solar 105

• New coal-fired 119

• “Wind is already the cheapest… solar PV will be cheaper than gas in 2017”

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Renewables can’t supply our needs ?

• Wind power supplied over 50 % of total power consumption of South Australia for August 2014

• On one September day it met 100 % of demand [& exported]

• Ellison, McGill & Diesendorf: all power needs now can be met from a mix of renewables

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Population Impact• SoE 1 (1996): cause of problems

• Australia’s Kyoto argument

• ACF EPBC Act submission

• Environmental impact I = P. A. T , so proportional to P unless Affluence declines or Technology improves faster than population grows

The numbers are:• “natural increase” ~ 150,000 per year

• Birthrate ~ 1.9 per adult woman, but number adult women increasing

• Net migration ~ 250,000 per year

• Refugee quota ~ 20,000

• Population growing > 1 million every 3 yrs

• Would be growing 1 million every 7 yrs if zero net migration now

Projections• Population stabilises in 2030s at

~ 28 million if zero net migration

• Stabilises later at higher level with net migration < 70,000

• At current migration rates and birthrate, 2050 population > 40 million, 2100 > 60 million