Anthropogenic Climate Change

1. Introduction

Researchers have deduced that climate change is mainly driven by anthropogenic activities globally. These activities have altered the Earth's energy budget, total gas emissions, concentration of gases in the atmosphere as well as land surface properties. It is generally accepted that the climatic parameters may also change due to natural processes. However, the impacts of human activities have led to abnormal fluctuations of these parameters against the background values. Some of the prominent evidence of climate change includes the increase of global mean surface air temperatures over the land and oceans, the remarkable increase of atmospheric CO2 concentrations globally and ocean acidification. In this report, the mitigation

These gases are believed to be the main cause of climate change. The three most well known greenhouse gases are CO2, CH4 and N2O. The concentrations of these gases in the atmosphere have increased drastically since the pre-industrial times. It is well documented that the increase in concentrations of these gases is caused by anthropogenic activities that includes the use of fossil fuels as well as agriculture. Apart from the atmosphere, the hydrosphere is also affected by this abnormal change in the concentrations of the mentioned gases. One of the few major consequences is the change in global ocean pH or known as the ocean acidification. In this report, the importance of CO2 as one of the main contributors to ocean acidification and how to reduce its concentration in the atmosphere is addressed

CO2 can be removed by means of climate-engineering methods. These methods involve the enhancement of terrestrial carbon sink and natural weathering processes, utilization of biomass for carbon sequestration, direct capturing of atmospheric CO2 and ocean fertilisation (The Royal Society, 2009). These techniques aim for an increase and uptake of carbon in the ocean and on land. The following section of this report aims to explain whether the use of ocean iron re-fertilisation is an effective method to reduce the effect of global warming.

2.1.4. Addressing the effectiveness of ocean iron fertilisation

According to Raven & Falkowski (1999), carbon cycle in the ocean is governed by two mechanisms namely the 'solubility pump' and the 'biological pump'. The circulation of warmer tropical waters (less dissolved CO2) and colder polar waters (more dissolved CO2) controls the solubility pump and on the other hand, the photosynthetic activity of phytoplanktons is what controls the biological pump (Rayfuse et al.,