The Main Drivers of Climate Change and Global Solutions

In this report, the drivers of climate change will be examined, both natural and anthropogenic, and solutions for the threat of climate change are looked at in relation to realistic routes for change in the Irish energy sector. It begins by looking at the natural drivers, such as the ENSO cycle, the Sun, geological processes like volcanoes and the orbital characteristics of the planet Earth. Then the anthropogenic factors, like deforestation and fossil fuels, are likewise examined. The solutions discussed include biomass, wave and tidal and carbon capture storage. The conclusion of the report is that the effects of the anthropogenic drivers are effecting the global climate more then the natural drivers and therefore causing global warming even though the natural drivers would predict a global cooling.

Introduction

The aims of this report are to discuss the natural and anthropogenic drivers of climate change. The objectives are to work out which of the two or both are causing the global warming. The earths temperature has risen by. 9 of a degree and is going to rise as the earth has a delayed response time in relation to atmospheric carbon and temperature rise. The current atmospheric carbon reading is approx. 412 ppm. Before the industrial revolution this reading was at 280 thousands of years and hadn’t rose above 350 ppm in 400,000 years, as was discovered by sampling bubbles of trapped air in ice sheets. The document is structured as a technical report, in the body of the report, the natural drivers are firstly examined, secondly, the anthropogenic drivers, and lastly, the solutions are discussed.

1. Natural Drivers of Climate Change

1.1 El Nino and La Nina

The ENSO is a term used to describe the fluctuations between the ocean and atmosphere in the east-central Equatorial Pacific. The ENSO (El Nino Southern Oscillation) has two opposite phases that affect the global climate, El Nino and La Nina. These periods can typically last 9-12 months but have been recorded to last years and they occur approximately every 2-7 years. The El Nino phase is brought about by strong winds blowing the opposite direction (Easterly) to the trade wind direction (Westerly). This causes a reduced amount of upwelling of cold water off the coast of South America. The effects of the El Nino are seen most obviously in North America during winter months. The warmer ocean causes the Jet Stream over North America to change course, bringing it further south. The effects are flooding and storms in the southern states and sunny dry weather to northern US and Canada. The opposite phase, La Nina, sometimes called the cold phase, occurs when the trade winds are stronger the usual and cause an increased upwelling of cold water next to the South American coast as the warm water is pushed across the Pacific towards Eastern Asia. The effects of this are large increases in rainfall in the Western Pacific, the colder ocean along the south American coast causes a northerly shift in the jet stream course over north America, leading to drought in the southern states and wet, cold weather in the northern states and Canada [1].

1.2 The Sun

The Sun is our most important source of heat and energy. As a star it produces energy by nuclear fission in its core. The sun is also what is known as a variable star, meaning it doesn’t always output the same amount of energy. Scientists in 1843 discovered an approximately 11-year cycle of increasing and decreasing amounts of energy emitted. This cycle can be tracked by the amount of dark areas (sunspots) and bright areas (faculae) on the sun’s surface, shown below in Figure 2.1

The energy output is highest at the time of the most sun spots and and faculae, although the difference between highest and lowest may be only 0.1%. During first half of the 1900’s there was a trend of increasing solar output, meaning the peak intensity of each solar cycle was increasing, leading to a tiny increase in global temperatures. Since 1970 the peak intesity has been dropping and therefore there should be a natural trend of decreasing global temperature due to lower sloar energy output. As this is not the case ther is obviously other factors affecting global warming [3].

1.3 Volcanos

Volcanic eruptions have an effect the global weather and climate. The eruptions shoot dust and ash high into the atmosphere, leading to a shielding effect as this blocks the Sun’s warmth from reaching the Earth’s surface [4]. There is a global cooling effect due to this. After Mount Pinatubo erupted the global temperature dropped 0.6 degrees. This is only a temporary effect though and temperatures return to the normal after a few years. Volcanoes can also contribute to the greenhouse effect as they emit large amounts of carbon dioxide and methane into the atmosphere, which are two greenhouse gases. This causes global warming by trapping the sun’s rays inside the atmosphere. Volcanic areas can contribute even when not erupting as fissures and cracks in the Earth’s surface can leak carbon dioxide and methane too. The effects of eruptions cooling the planet is temporary and the emission of greenhouse gases causing the greenhouse effect is a very tiny portion of the overall global warming [3].

1.4 Orbital Characteristics

The Earth’s orbit of the sun determines the climate to a large degree. The Earth’s orbit varies from an ellipse to a near perfect circle throughout a 100,000-year cycle. This changes the way energy from the sun is distributed across a very long time period. Earth’s axis, which is responsible for the seasons, varies its degree of tilt too, between 22.1 and 24.5. It is currently at 23.5 degrees and changes to this angle would result in large changes the seasons length and characteristics [3].

2. Anthropogenic Drivers of Climate Change

2.1 Deforestation

Anthropogenic means human-influenced. Deforestation is clearly an anthropogenic factor as humans are the ones clearing the rainforests. The financial gain that comes with clearing land for agriculture is most clearly seen in Brazil. The Amazon Rainforest is the world’s largest carbon sink, yet since 1978 over 750,000 square kilometres of the rainforest has been cleared [4]. The largest driver of deforestation at the current time is land for cattle-ranching. there are over 200 million head of cattle in Brazil, they are the no. 1 exporter of beef in the world [5]. The huge numbers of cattle contribute to global warming as cattle emit large amounts of methane, which is of course a greenhouse gas. The soil of the Amazon is not suitable for long term grass growth yet is very fertile during the immediate years after being deforested. Once the soil becomes incapable of growing grass, more forest is cleared. The land is abandoned by the ranchers to the agricultural plantations, namely palm oil, for intensive fertiliser heavy farming. The global effect of the clearing of rainforests is the reduced intake of CO2 and therefore increased levels in the atmosphere, increasing the greenhouse effect from CO2. Deforestation of the Amazon also effected the global weather systems. For example, if the rainforest is reduced to a point where the Amazon river begins to lose size and power, the currents in the ocean off South America would change affecting the jet stream changing the global weather along it [6].

2.2 Fossil Fuels

In the late 1700’s, the Industrial Revolution took place. Humans began burning fossil fuels, fuels high in carbon. This released the trapped carbon into the air forming carbon dioxide which is a greenhouse gas. The greenhouse effect itself is necessary for life to survive on earth, without it the Earth’s average temperature would be almost 16 degrees Celsius colder. The amount of carbon in our atmosphere is usually measured in carbon ppm (parts per million). Before the 19th century it was sitting at 280 approx. hundreds, if not thousands of years. It is now measured at over 400 ppm [7], the highest amount in over 400,000 years as seen in Fig 3.1. This is due to the continued reliance on fossil fuels for energy for a growing human population. Fossils fuels account for 80% of global energy presently, which is lower then it used to be. New technology in renewable and sustainable energy, i.e. nuclear, wind, bioenergy, has slightly reduced reliance on fossil fuels but not nearly enough to make a significant impact on the rising levels of atmospheric CO2.

The effects of global warming can lead to many different natural disasters. The increased frequency of tropical storms and hurricanes in North America have been associated with global warming interfering with the natural weather processes in the Atlantic Ocean [8]. Global temperatures have risen. 9 degrees Celsius and have risen more in polar regions causing the ice caps to begin melting. If all the ice caps do melt it would result in a rise in sea levels by 216 feet [9]. This is unlikely to happen in our lifetime, yet it is a possibility in the next hundred years. The rising sea level would make Ireland into a cluster of small islands. Finally, global warming has increased the rate of desertification in areas like the Sahel which are sensitive to climate changes. The rainfall in the Sahel region has decreased by 30% in the last 20 years making the land more barren due to calcification and salinization of the soils by capillary action. The Sahara Desert is spreading in all direction at a rate of 9 km per year, displacing hundreds of thousands of people as they are forced to move further south or to cross the Mediterranean. These sorts of people are known as “climate refugees”, people forced to leave their homes due to changing climate [4]. If the sea levels rise from only quarter of the ice melting then there will be millions of climate refugees across every continent.

3. Solutions

3.1 Biomass

The Irish people are still very reliant on fossil fuels for their energy needs, with gas boilers, coal burning power stations and gas being pumped from Siberia. The need to find a sustainable solution is becoming increasingly necessary for financial and energy security soon. Therefore, the natural advantages of the Irish landscape and resources must be used. The climate of Ireland encourages the growth of trees like willow as a biomass solution to coal burning. This is a carbon neutral source of energy. Moneypoint is Irelands largest coal burning power station, if it was converted to biomass then the CO2 output of Ireland would be reduced by the 200 million tonnes of carbon dioxide it pumps out every year [4]. The biomass would have to be shipped from America or somewhere else suitable to begin with, but Irelands climate allows for a much faster yield of biomass crop then France, for example. The willow grows to the proper size in just 5 years in Irish conditions compared to France’s 8-year growth cycle. The government would have to give tax cuts or incentives for farmers to change to biomass crop growth, but it would benefit areas with poor soil and bad quality land such as Donegal and parts of Connacht [4].

3.2 Wave and Tidal

Ireland also has a huge untapped potential in wave and tidal energy. It is estimated that there is 7 gigowatts of energy available if the entire west coast of Ireland was fitted to take advantage of the wave and tidal energy. To put this in perspective Irelands entire energy generation is 10 gigowatts, and almost 85% of that is imported. This supply of energy from the natural resource wold not only go a long way towards meeting our energy targets but would also bring energy security to the country [11].

3.3 Carbon Capture Storage

One technology that Ireland has not yet embraced is Carbon Capture Storage. It is a process that can remove up to 90% of the carbon dioxide coming out of an electricity power generating or industrial plant [12]. The CO2 is then piped or shipped for storage. The technology to properly manage the stored CO2 emissions is not trustworthy yet as there have been reported side effects from piping the CO2 deep into the Earth’s crust, such as small earthquakes and cracks forming on the cap rock of the carbon storage areas, which could in time become carbon leaks, e.g. Sleipner, Norwegian North Sea [13]. The technology has to be brought forward as it is a very good way to reduce emissions. If CCS is used with a power plant fuelled by biomass, it would be a carbon negative process [12].

3.4 Global Solutions

The global problem of climate change is a lot more difficult to fix as each country has their own views and measures in place to combat it or to ignore it. The solution to the problem would be if every country that had the means to, began or increased research and innovation into new strategy’s and technology’s for renewable energy.

4. Conclusion

The findings of this report show that the drivers of climate change are largely anthropogenic. This is clearly seen by how the natural drivers of climate change are favouring a slight global cooling effect, and as this is not the case the only conclusion is that the climate change we are experiencing now is human-induced. This is why scientists are calling this time period the Anthropogenic Period as humans are for the first time in history the biggest factor effecting the global climate.