Carbon, an essential part of all organic molecules, is found in the atmosphere, and exchanged to it, as carbon compounds such as carbon dioxide, CO2, and methane, CH4. These compounds have an important role regulating the earth’s temperature as heat is trapped by the atmosphere. Carbon dioxide and methane are often referred to as greenhouse gases (GHGs). GHGs also includes water vapour and nitrous oxide, N2O, and ozone. Greenhouse gases absorb and emits radiant energy within the thermal infrared range and their concentrations in the atmosphere have an important and necessary effect in regulating the earth’s temperature; without them the earth’s surface temperature would be too low to make it habitable as we know it, and the relatively recent increases in the levels of GHGs are causing temperature increases that could potentially be irreversible, or difficult to stop or reverse. Figures 1 to 6 show the historical stability and recent increases in the levels of atmospheric carbon dioxide, nitrous oxide, methane, global sea level. the associated decrease in the level of oxygen, and the rise in global atmospheric temperature. Carbon dioxide and nitrous oxide levels are linked to vehicle engine emissions although much higher levels are linked to respiration; methane emissions are linked to agriculture and particularly the ruminant’s cattle and sheep.
In understanding the role of how carbon in the atmosphere causes changes in temperature in the atmosphere and on the planet’s surface, and consequently changes in climate, it is useful to have some understanding of the global carbon cycle and how this understanding can help lead to some of the solutions to the current problem. The carbon cycle is the biogeochemical cycle by which carbon is exchanged between the biosphere, pedosphere, geosphere, hydrosphere, and atmosphere of the Earth. Figure 7 is a typical example of a diagram that can be found when browsing the internet, and although the numbers may change on similar comparable diagrams the magnitudes shown are representative and can be related to Figures 1 to 6.
The internet data sources for Figures 1 to 6 allow for close online inspection of the data. After relative stability for the previous centuries, the pattern of data for carbon dioxide, methane and nitrous oxide is similar with levels starting to increase by the end of the nineteenth century and rising sharply by the end of the twentieth century. This is reflected in the similar pattern of rise in global temperatures.
In understanding the role of how carbon in the atmosphere causes changes in temperature in the atmosphere and on the planet’s surface, and consequently changes in climate, it is useful to have some understanding of the global carbon cycle and how this understanding can help lead to some of the solutions to the current problem. The carbon cycle is the biogeochemical cycle by which carbon is exchanged between the biosphere, pedosphere, geosphere, hydrosphere, and atmosphere of the Earth. Figure 7 is a typical example of a diagram that can be found when browsing the internet, and although the numbers may change on similar comparable diagrams the magnitudes shown are representative and can be related to Figures 1 to 6.
In Figure 7, a Pg is equivalent to a Giga tonne, or one billion tonnes. The ocean loss and uptake of carbon, photosynthesis and plant and soil respiration are close to being in balance with a small net carbon sequetration, but unable to netralize the emissions combined from, deforestation, land use change and burning fossil fuels, the net effect of which is the increase in atmospheric concentrations of carbon dioxide, methane and nitrous oxide. The effect on climate is the resulting temperature rise seen in Figure 6, and this results in ice melt causing the sea rise seen in Figure 4. No action to stop or reverse the increase in global temperatures is predicted to increase the rate of sea level rise and to cause increased weather instability and the seriousness of severe weather events.
The BBC has presented some of the basic data used in climate change debate in seven charts some of which are animated aginst timelines (Climate change: Where we are in seven charts, 18 April 2019):
Climate change: Where we are in seven charts
The current solutions that effect terramechanics
Although still under heavy criticism for the need for even more action to reduce the emission of GHGs, the UK government has acceted into law the recomendations of its Climate Change Committee to achieve zero net carbon emmissions by 2050. The UK Climate Change Committee published two reports in May 2019 (www.theccc.org.uk/publications ) to recomend the net zero target and to provide quantitative evidence on how this target can be achieved, but without clear policy routes to acheive the targets (more information and a report summary is available in the "Relevant Reports" page. The main proposals include: the continued move to renewable energy, the more efficient use energy, the move to electical vehicles (the UK has set a deadline of 20140 for this), afforestation and reforestation, land use that promotes carbon capture and storage (CCS), and agricultural practice that reduces carbon emissions and supports dietry change that redusces methane emissions, carbon emissions generally, and requires less land to support the food required.
For terramechanics this supports the development of electric powered vehicles using renewable energy, including the development of drivelines, wheel drives and their control. The emphasis on forestry and reforestation should provide considerable boost for sustainable forestry management and mechanization. The focus on low carbon emissions from agriculture and soil management that promotes CCS and other ecological soil services, including biodiversity, should also provide incentives for agricultural engineering research linked to terramechanics.