critical thinking.

CLIMATE CHANGE: APPRAISAL OF ARTICLES
Theresa WoghirenUniversity
Climate Change: Appraisal of Articles
Current Understanding
Climate change refers to the change in the statistical distribution of weather patterns and such changes last for an extended period of time. Such changes in climate are brought about by both biotic and abiotic factors. The biotic factors include human and animal activities while abiotic factors include solar radiation, movement of tectonic plates and eruptions of volcanoes. Climatic changes may be spontaneous or it may be induced. Such changes cause devastating effects on human and animal life. Further, changes in climate brings about destruction and changes in the properties of soil, water and air which impacts various ecosystems. I have an opinion that increased carbon-dioxide is responsible for global warming and emission of carbon dioxide cannot be controlled. Global warming or increase in surface temperature of the earth is caused by the emission of various gases of which carbon-dioxide is the main gas. Green gases lead to trapping of ultraviolet radiation within the surface of the earth and prevent its reflection back into the atmosphere. The increased temperature causes melting of ice caps and raising the sea water level with increased risk of floods and danger to agricultural and inhabitable lands.
Appraisal of Articles
The two articles (Petit et al.

, 1999, Solomon et al., 2009) provided an in depth analysis on global warming.
Reference Article 1: Petit, J. R.; Jouzel, J.; Raynaud, D.; Barkov, N. I.; Barnola, J.-M.; Basile, I.; Bender, M.; Chappellaz, J.; Davis, M.; Delaygue, G.; Delmotte, M.; Kotlyakov, V. M.; Legrand, M.; Lipenkov, V. Y.; Lorius, C.; Ritz, C.; Saltzman, E. (1999). “Climate and atmospheric history of the past 420,000 years from the Vostok ice core, Antarctica”. Nature, 399 (1), 429–436.
The article provided insights into the findings from the drilling at Vostok Station in East Antartica. The findings reflected the changes in atmosphere and climate features in the last four glacial/interglacial periods. The succession of changes that occurred in each such cycle was found to be similar and the termination or climax happened in a similar way. The atmospheric and climatic properties oscillated in such cycles. It was found that although the glacial periods and timings between such periods differed, there was an equal prevalence of carbon dioxide and methane in all such periods. The study thus concluded that, both carbon-dioxide and methane are equally responsible for causing “green house effect” over the past 4, 00,000 years.
Reference Article 2: Solomon, S., Plattner, G., Knutti, R., & Friedlingstein, P. (2009). “Irreversible climate change due to carbon dioxide emissions”. Proceedings of the National Academy of Sciences of the United States of America, 106 (6), 1704–9.
The article indicated that climate changes that take place due to changes in carbon-dioxide concentration remains irreversible for at least 1000 years, after emission of carbon dioxide stops. When the emission of carbon dioxide ceases, radiative forcing is decreased. This is compensated by slower and lesser loss of trapped into the ocean and hence the atmospheric temperature (global warming) does not drop significantly in at least 1000 tears. The predicted effects of increased carbon dioxide from 385ppmv to 450-600ppmv over the coming century will lead to reductions in rainfall and unprecedented rise in sea water levels. The rise in sea water levels will also be potentiated through contributions from glaciers and ice sheets.
The articles appraised above provided credible information since both these articles reflected the opinion of National Research Council and National Academy of Sciences, USA. The authors are credible since they are competent and renowned environmental scientists and critiques. No, the articles are not quasi-credible; they are credible because relevant data has been used to support the hypotheses.
Reflection
Yes, my opinion has changed regarding global warming after reading these two articles. Earlier I believed that carbon dioxide is the chief gas responsible for global warming. However, the articles indicated the equal potential of other gases in contributing to the issues of global warming. Further, I believed that reduction in carbon dioxide emissions will reverse the changes in climate.
In fact, the articles indicated once the climate is changed, reduction of emission of carbon dioxide or any other green gases cannot alleviate the changes. The second article was more convincing because it portrayed with facts and figures that carbon dioxide emissions may lead to irreversible climatic changes including the severe impacts of global warming.
Quantitative analysis of climatic data through time period analysis is required to change my opinion. This is because the second article made quantitative predictions, and it is possible to re-estimate such changes if the determinant variables are identified and standardized.
References
Petit, J. R.; Jouzel, J.; Raynaud, D.; Barkov, N. I.; Barnola, J.-M.; Basile, I.; Bender, M.;
Chappellaz, J.; Davis, M.; Delaygue, G.; Delmotte, M.; Kotlyakov, V. M.; Legrand, M.;
Lipenkov, V. Y.; Lorius, C.; Ritz, C.; Saltzman, E. (1999). “Climate and atmospheric
history of the past 420,000 years from the Vostok ice core, Antarctica”. Nature, 399 (1),
429–436.
Solomon, S., Plattner, G., Knutti, R., & Friedlingstein, P. (2009). “Irreversible climate
change due to carbon dioxide emissions”. Proceedings of the National Academy of
Sciences of the United States of America, 106 (6), 1704–9.