Transcript The energy imbalance cause by human and natural activities

Environmental Services Training Group
LOCAL AUTHORITY ENVIRONMENT CONFERENCE
2015
Protecting Our Environment
Hodson Bay Hotel, Athlone, May 2015.
1
Protecting Our Environment
Climate Change Implications for Ireland
Frank McGovern
Senior Manager
Environmental Protection Agency
Content
 The issues
 Drivers of climate change
 Current and projected changes
 Response options
 Pathways to a 2C World
It Additional energy/Radiative Forcing
The energy
imbalance cause
by human and
natural activities
Expressed as extra
energy per square
meter.
Total 2.29 W m-2
GHGs alone 2.83 W
m-2
Where is the energy going?
More than 90% of
the excess energy
has been stored in
the ocean
Melting of ice
(glaciers) and up-take
by land accounts for
most of the remaining
energy
The Ocean has also
taken up about 30%
of the excess carbon
dioxide
Some observed changes
Observed changes are unprecedented
over decades to millennia
Surface temperature increase 0.85C since
1880s, ice cover has reduced and sea level
has risen
Changes in rainfall patterns and melting of
snow and ice have had adverse impacts
on water resources
The impacts are most evident in the
natural world; many terrestrial which are
moving to cooler regions and some
extinctions have occurred
Food production has been negatively
impacted with reduced maize and wheat
yields. Some positive impacts, in some
regions, for some crops
GHG emissions since 1970
Sources of emissions in 2010es of
emissions
35%
Energy Sector
24%
Agriculture,
forests and
other land uses
21%
Industry
14%
Transport
6.4%
Building
Sector
AR5 WGIII SPM
Energy production remains the primary driver of GHG emissions
The main CO2 sources
Impacts are already happening
•
•
•
Tropics to the poles
On all continents and in the oceans
Affecting rich and poor countries
Projections of future climate
Oceans will continue to
warm throughout this
century
It is very likely that the
Arctic sea ice cover will
continue to shrink and thin
as global mean surface
temperature rises
Global mean sea level
will continue to rise
during this century
Global glacier volume will
further decrease
Continued emissions of greenhouse gases will cause further
warming and changes in the climate system
Potential Impacts of Climate Change
Food and water shortages
Increased poverty
Increased displacement of
people
Coastal flooding
The Future: possible pathways
Sea level rise 2100 relative to 2010,
Low emissions
High emissions
26 - 55cm,
45 – 82cm
2˚C
The window for action is limited
Amount
Remaining:
275
Total Carbon
Budget:
790
GtC
GtC
Amount Used
1870-2011:
515
GtC
AR5 WGI SPM
65% of our carbon budget compatible with a 2°C goal already used
Stabilization of the climate system
~3°C
Based on Figure 6.7
AR5 WGIII SPM
Mitigation options
More efficient use of energy
Greater use of low-carbon and no-carbon energy
• Many of these technologies exist today
Improved food production and carbon sinks
• Reduced deforestation and improved forest management
and planting of new forests
• Bio-energy with carbon capture and storage
Lifestyle and behaviour changes
AR5 WGIII SPM
Limiting the Global temperature Increase to 2˚C
To have a likely chance (66%) of keeping the global temperature increase to
below 2°C requires global GHG emissions to be
 Reduced by between 40% and 70% relative to 2010 levels by 2050

and be near or below zero by 2100
Higher emissions to 2050 implies more reliance on negative emissions in
the 2nd half of the century.
This is a high risk approach due the availability, and scale, of technologies to
achieve this are uncertain.
Ambitious Mitigation is Affordable
➜
Economic growth reduced by ~ 0.06%
(BAU growth 1.6 - 3%)
➜
This translates into delayed and not forgone growth
➜
Estimated cost does not account for the benefits of
reduced climate change
➜
Unmitigated climate change would create increasing
risks to economic growth
Responses
The choices we make now will determine the level of future risks
• Substantial and sustained reductions in greenhouse gas emissions
are needed to reduce climate change related risks
•
Full de-carbonisation of energy and sustainable land and biomass
management are key parts of this
• Adaptation to reduce the adverse impacts of on-going and
unavoidable climate change
• A risk based approach can assist in adaptation planning
• Addressing current vulnerability/exposure is first step in adaptation
Conclusions
 The human influence on the climate system is clear
 The more we disrupt our climate, the more we risk severe,
pervasive and irreversible impacts
 We have the means to limit climate change and build a more
prosperous, sustainable future
 Effective policies and technologies are central to the required
transformation
Thank you