Is Greenhouse Gas Emissions Responsible for the Global Climate Change

Introduction

The aim of this report is to evaluate to what extent anthropogenic greenhouse gas emissions are responsible for recent global climate change (Karl and Trenberth, (2003), and to identify the main uncertainties associated with future climate modelling. These queries are firstly explored by analyzing the effects that natural causes such as solar volcanic eruptions and solar output have had on recent global climate. This is then contrasted by looking at the volumes of greenhouse gases that are anthropogenically emitted and the observed effects of this. Finally, uncertainties over future emissions and climate modelling are discussed, along with its associated implications.

3. Materials and methods

Anthropogenic climate change is the belief that greenhouse gases (CO2, NO2 and CH4) emitted by human activity are to blame for the rapid increase in global temperature seen since the industrial revolution (Fig. 1).

Anthropogenic climate occurs through the enhanced greenhouse effect. This is where solar radiation travels through the surface, which then absorbs and reflects

atmosphere to the earth’s surface, which absorbs and reflects this energy back at IR wavelength (700nm-1mm).

About 70% of solar energy is absorbed by the Earth’s surface and lower atmosphere, with the rest being reflected back to space through clouds and albedo (NASA, 2013).

The absorbed radiation warms the planet (Fig. 2) by being re-radiated into the atmosphere, where some of it gets absorbed by greenhouse gases like water vapour and carbon dioxide. These gases then radiate that heat back towards Earth, heating the lower atmosphere and surface, thus enhancing the heating they get from direct sunlight (NASA, 2013).

So we must look as to what ext...

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...egy is put into action, a doubling of CO2 in the atmosphere will result in a 1.5-4.5C increase in global surface temperatures

4. Results and Interpretation

The range of IPCC global surface temperature predictions are quite large from year to year. This is partly to do the uncertainty of future emissions, but also, probably most importantly, due to uncertainties in climate modelling.

This is because while the effect of increased greenhouse gas emission on the climate is well understood, the effects of several positive feedback loops as a result of this, aren’t, so they’re not properly accounted for in the models.

5. Conclusion

So, to summarise:

 Anthropogenic climate change happens due to enhanced greenhouse effect and deforestation of carbon sinks.

 Recent climate change is partly due to volcanic eruptions and changes in solar output, but an