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Climate change report To what extent are the causes of climate change natural?

Climate change report
To what extent are the causes of climate change
natural?

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Climate change report
To what extent are the causes of climate change
natural?

Luka Perkins Petit – 15 February 2017
Introduction



Global climate change is defined as a worldwide variation in temperature and
weather, observable as a trend everywhere on the planet. It is caused by natural factors
but greatly accelerated by human drivers. Throughout history, natural events such as
sunspots, increased volcanic activity and ice ages have drastically changed earth’s climate.
However, global temperatures have risen at an alarming rate in a very short timeframe.
This has started since the industrial revolution in the early 20th century.
Natural drivers



Global climate is affected by natural factors such as changes in solar energy outputs,
volcanic activity, and the Earth’s orbit around the Sun. But the two factors that really affect
climate change on a contemporary timescale are changers in volcanic activity and solar
radiation. But volcanic eruptions are patchy and have a more short term effect on climate.
Solar radiation, with a pattern known as the Milkanovitch cycle, has been instrumental in
climate trends since observable history. However, the consequences of human activity
related greenhouse gas emissions have 51 times more effect on the atmosphere than do
changes in solar output.
In figure 1, we can observe the positive
correlation between global temperature and
solar activity. Figure 2 below shows the trend in
volcanic eruptions since 1945, with no
observable increase in new eruptions. Volcanic
activity does not contribute too Global climate
change, at least not in our restricted timeframe
of post-industrialisation.
CLIMATE CHANGE REPORT – LUKA PERKINS PETIT 1
Fig 1, NASA GISS – Global temp. VS Solar activity
Human drivers
According to a 2016 paper (co-authored by Naomi Oreskes and others), there is a 97%
consensus among climate scientists that humans are causing recent global warming. The
evidence seems to be overwhelming that because of increased CO2 emissions since the
industrial revolution, global temperatures are
rising. Figure 3 shows carbon dioxide variations
over the past 400 000 years, in parts per million.
This data unequivocally proves that since the
industrial revolution, the CO2 concentration in the
atmosphere has risen unnaturally. Factories, cars,
planes, have all contributed to saturating the air
with the heat-trapping particle CO2. Furthermore,
deforestation is not helping, since trees are known to
convert CO2 to oxygen.
The Consequences
NASA’s research (Fig. 4) shows that global sea levels
have risen over 17 cm in the past century. This
makes seaside population vulnerable to flooding
and habitat destruction.
Rising sea level is linked to melting of ice caps (Fig.
5). Once again according to NASA,
Antarctica lost about 152 cubic kilometers
(36 cubic miles) of ice between 2002 and
2005. Shrinking ice sheets go hand in hand
with rising temperatures. We are now
approaching almost 1 degree Celsius higher
than pre-industrialisation levels.
CLIMATE CHANGE REPORT – LUKA PERKINS PETIT 2
Fig 2, Global Volcanism Program – New volcanic
eruptions per year
Fig 3, Marland, G., T.A. Boden, and
R. J. Andres. 2003. – CO2 variations
Fig 4, NASA – Sea Level Change
Fig 5, NASA – Antarctica ice mass
decrease
Consequences of global climate change are catastrophic for the human race as well as all
fauna and flora. Climatic imbalances cause extreme events such as hurricanes, flash floods
and increasing levels of intense rainfall. The acidity of surface ocean waters has also
increased by 30% since pre-industrialisation levels. The result of ocean acidification is
coral bleaching and changes in ocean chemistry which lead to cascading effects
throughout ecosystems.
The future of climate change
According to how we, humans, mitigate the effects we have had on climatic systems,
predictions of future climate change vary widely. The above Fig. 6, created by Environment
and Climate Change Canada, show global temperatures in 2081-2100 according to the
solutions we find to reverse the effects of mass CO2 emissions. On the left hand is a bestcase
scenario which requires zero, or negative emissions to maintain temperature change
below 2ºC before the end of the century. On the right is a “business as usual” type
scenario.
The IPCC affirms that all systems such as water, ecosystems, food, coasts and health, will
be ruptured. They suggest decreasing water availability will cause widespread drought,
signifiant extinctions will wipe out over 50% of species, agricultural productivity will
decrease in low latitudes, millions of people could experience flooding, as well as
malnutrition, diaorreal, infectus diseases and heart problems that might put significant
pressure on healthcare services. IPCC experts based their predictions upon the scenario
that the earth’s temperature will rise to +5ºc (right hand Fig.6).
CLIMATE CHANGE REPORT – LUKA PERKINS PETIT 3
Fig 6, ECCC- Global
temperature predictions
The path we are on is uncertain, however the UN and inter-governmental
organisations are working on a better climatic future. The most recent international
summit for climate change was the COP 22, in Marrakesh. Negotiators from 200 countries
met and tried to concretise the COP21 paris agreements into a workable plan. All
countries have affirmed their “commitment” to the “full implementation” of the Paris
Agreement. But much remains to be done to curb global temperatures and reduce CO2
emissions, especially with LEDC’s who have a heavily vested interest in continuing their
use of cheap (but carbon heavy) fuels. In the past, agreements such as the DDT ban in
1972 have worked to prevent further environmental pollution. In fact, the hole in the
ozone layer
Conclusion
Evidence points unequivocally towards human activity as the cause of recent climate
change. Through the burning of fossil fuels, we have been polluting the atmosphere to the
extent that greenhouse gases are causing global temperatures to rise. Climate skeptics still
argue that temperature change is natural, but it is time to accept the concrete evidence that
we, though our reckless relationship with the atmosphere and nature for economic
benefit, are digging our own grave. Natural drivers also have an effect, but as previously
demonstrated in figure 1 and 3, they are almost trivial.
The most disheartening fact I learnt is that we need 0 emissions, or negative
emissions to stabilise climate change at +2ºc (Fig. 6). This is hardly realistic, especially
when periphery countries are pushing to become core countries and want the same cheap
energy most MEDC’s built their industries on. I believe that the solution to global climate
change lies purely in financial and economical aspects. Make sustainable energy cheaper
than fossil fuels, and we will be one step further towards a zero-emissions world.
CLIMATE CHANGE REPORT – LUKA PERKINS PETIT 4
Sources:
“Read “Ocean Acidification: A National Strategy to Meet the Challenges of a Changing
Ocean” at NAP.edu.” 4 Effects of Ocean Acidification on Marine Ecosystems | Ocean
Acidification: A National Strategy to Meet the Challenges of a Changing Ocean |
The National Academies Press. N.p., n.d. Web. 19 Feb. 2017. <https:// www.nap.edu/read/12904/chapter/6>.
Church, J. A. and N.J. White (2006), A 20th century acceleration in global sea level rise,
Geophysical Research Letters, 33, L01602, doi:10.1029/2005GL024826.
“Climate Science Glossary.” Skeptical Science. N.p., n.d. Web. 19 Feb. 2017. <https:// skepticalscience.com/climate-best-to-worst-case-scenarios.html>.
“Environment and Climate Change Canada – Climate Change – The Science of Climate
Change.” Government of Canada, Environment and Climate Change Canada. N.p.,
24 Nov. 2015. Web. 19 Feb. 2017. <http://www.ec.gc.ca/sc-cs/Default.asp? lang=En&n=A5F83C26-1>.
“Countries at COP22 Pledge to Press Ahead with Paris Agreement.” United Nations.
United Nations, n.d. Web. 19 Feb. 2017. <http://www.un.org/ sustainabledevelopment/blog/2016/11/countries-at-cop22-pledge-to-press-aheadwith-implementation-of-paris-agreement/>.
“Ocean Acidification.” Ocean Acidification. N.p., n.d. Web. 19 Feb. 2017. <http:// www.pmel.noaa.gov/co2/story/Ocean+Acidification>.
“Climate Change Evidence: How Do We Know?” NASA. NASA, 06 Dec. 2016. Web. 19
Feb. 2017. <https://climate.nasa.gov/evidence/>.
Bray, Dennis; Hans von Storch (1999). “Climate Science: An Empirical Example of
Postnormal Science” (PDF). Bulletin of the American Meteorological Society. 80 (3):
CLIMATE CHANGE REPORT – LUKA PERKINS PETIT 5
439–455. Bibcode:1999BAMS…80..439B. doi:
10.1175/1520-0477(1999)080<0439:CSAEEO>2.0.CO;2. ISSN 1520-0477. Retrieved
2007-09-04.
Cook, John; Oreskes, Naomi; Doran, Peter T.; Anderegg, William R. L.; Verheggen, Bart;
Maibach, Ed W.; Carlton, J. Stuart; Lewandowsky, Stephan; Skuce, Andrew G.;
Green, Sarah A. (2016), “Consensus on consensus: a synthesis of consensus estimates
on human-caused global warming”, Environmental Research Letters, 11 (44), doi:
10.1088/1748-9326/11/4/048002048002
“Facts on Climate Change – Causes of Climate Change.” Government of Canada,
Environment and Climate Change Canada. N.p., 27 Nov. 2015. Web. 19 Feb. 2017.
<http://www.climatechange.gc.ca/default.asp?lang=En&n=65CD73F4-1>.

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