Photo essay

Liceul Academiei de Ştiinţe a Moldovei, Republic of Moldova

1. Photo essay

Global warming uf obligation developed countries to combat climate change

ARGUMENT:

“It is man-made and it is essentially [caused by] fossil fuel burning,

Increased methane production… and so on.”

(Professor David King).

Climate change is happening and humans are contributing to it! No one disputes that Earth’s climate is changing or that atmospheric concentrations of greenhouse gases have increased as a result of human activities. The concentrations of carbon dioxide, methane, and nitrous oxide are higher now than at any time during the last 420,000 years.

Overwhelming scientific evidence supports the conclusion that observed changes in the global climate are, in large part, due to human activities and primarily related to fossil-fuel consumption patterns. Without urgent action to curb greenhouse-gas emissions, the Earth will become warmer by 2050 than at anytime in the last 10,000 years.

Temperatures provide the clearest evidence that the climate is changing and globally the average temperature has risen by more than 0.7 °C over the last 100 years.
The natural greenhouse gas effect keeps Earth much warmer than it would otherwise be, without it Earth would be extremely cold. Greenhouse gases such as carbon dioxide, methane and water vapor behave like a blanket around Earth. These gases allow the Sun’s rays to reach Earth’s surface but impede the heat they create from escaping back into space.

Any increases in the levels of greenhouse gases in the atmosphere mean that more heat is trapped and global temperatures increase - an effect known as ‘global warming’.

There is indisputable evidence from observations that the Earth is warming. Concentrations of CO2, created largely by the burning of fossil fuels, are now much higher, and increasing at a much faster rate, than at any time in the last 600,000 years. Because CO2 is a greenhouse gas, the increased concentrations have contributed to the recent warming and probably most of the warming over the last 50 years..

The rise in global surface temperature has averaged more than 0.15 °C per decade since the mid-1970s. Warming has been unprecedented in at least the last 50 years, and the 17 warmest years have all occurred in the last 20 years. This does not mean that next year will necessarily be warmer than last year, but the long-term trend is for rising temperatures.

A simple mathematical calculation of the temperature change over the latest decade (1998-2007) alone shows a continued warming of 0.1 °C per decade. The warming trend can be seen in the graph of observed global temperatures. The red bars show the global annual surface temperature, which exhibit year-to-year variability. The blue line clearly shows the upward trend, far greater than the uncertainties, which are shown as thin black bars. The recent slight slowing of the warming is due to a shift towards more-frequent La Niña conditions in the Pacific since 1998. These bring cool water up from the depths of the Pacific Ocean, cooling global temperatures.

The purpose of the research: The ample studying of the projects from the ecological problems compartment, especially those concerning climate change and its influence on Earth’s future.

The current climate change is not just part of a natural cycle. Earth’s climate is complex and influenced by many things, particularly changes in its orbit, volcanic eruptions, and changes in the energy emitted from the Sun. It is well known that the world has experienced warm or cold periods in the past without any interference from humans. The ice ages are good examples of global changes to the climate, and warm periods have seen grapes grown across much of Britain.

Over the several hundred thousand years covered by the ice core record, the temperature changes were primarily driven by changes in the Earth’s orbit around the Sun. Over this period, changes in temperature did drive changes in carbon dioxide (CO2). Since the Industrial Revolution (over the last 100 years), CO2 concentrations have increased by 30% due to human-induced emissions from fossil fuels. The bottom line is that temperature and CO2 concentrations are linked. In recent ice ages, natural changes in the climate, such as those due to orbit changes, led to cooling of the climate system. This caused a fall in CO2 concentrations which weakened the greenhouse effect and amplified the cooling. Now the link between temperature and CO2 is working in the opposite direction. Human-induced increases in CO2 are driving the greenhouse effect and amplifying the recent warming.

The Earth is heated by the sun; solar radiation passes through the atmosphere and is absorbed at the Earth’s surface (except for a small portion that is reflected back into space). This heat is readily lost; it is emitted from the surface as infra-red radiation. Fortunately, this infra-red radiation cannot escape the atmosphere as easily as the solar radiation can enter. Instead, some of it is ‘trapped’ by a number of gases; these gases act in a similar, yet different, way to the glass in a greenhouse - heat is allowed in but cannot get out - hence we have the ‘Greenhouse Effect’. Were it not for this natural greenhouse effect the Earth would be at least 30°C cooler and life as we know it would not exist. Unfortunately, recent human activities are enhancing the natural greenhouse effect. The concentrations of certain greenhouse gases in the atmosphere are increasing therefore more of the infra-red radiation emitted by the Earth’s surface is being trapped. The planet is losing less heat and as a result we are beginning to experience “Global Warming”. The major greenhouse gases are: water vapor, carbon dioxide, methane, nitrous oxide, CFCs (and their replacements), and ozone. Some of these occur naturally, some result only from human activity, while others occur both naturally and as a result of human activity. The contribution of each gas to the greenhouse effect is a function of three factors: Atmospheric lifetime - simply, how many years the gas remains active in the atmosphere; Global warming potential (GWP) - a relative measure of how effective the gas is at preventing the passage of infra-red radiation; Atmospheric concentration - usually measured in parts per million.

If we continue emitting greenhouse gases this warming will continue and delaying action will make the problem more difficult to fix. The global average temperature will increase by 2 to 3 °C this century – according to one of the Intergovernmental Panel on Climate Change’s (IPCC) mid-range estimates (blue line on the graph below). This rise in temperature means that the Earth will experience a greater climate change than it has for at least 10,000 years and it would be difficult for many people and ecosystems to adapt to this rapid change.

A major source of carbon dioxide is the power plants. These power plants emit large amounts of carbon dioxide produced from burning of fossil fuels for the purpose of electricity generation. Coal is the major fuel that is burnt in these power plants. Coal produces around 1.7 times as much carbon dioxide per unit of energy when flamed as does natural gas and 1.25 times as much as oil. The coal gives out eighty percent more carbon per unit of energy it produces as compared to natural gas. Another major source of carbon dioxide in the atmosphere is the emission from the cars and other vehicles. About twenty percent of carbon dioxide emitted in the atmosphere comes from burning of gasoline in the engines of the vehicles. This is true for most of the developed countries. Moreover if sports bike and vehicles that are essentially designed for rough terrain, emit more carbon dioxide when used for general purpose on roads.

It is always better to use vehicles designed for city driving on the city roads. Buildings, both commercial and residential represent a larger source of global warming pollution than cars and trucks. Building of these structures requires a lot of fuel to be burnt which emits a large amount of carbon dioxide in the atmosphere.

The second major greenhouse gas after carbon dioxide, which causes global warming, is Methane. Methane is more than 20 times as effectual as CO2 at entrapping heat in the atmosphere. Methane is obtained from resources such as rice paddies, bovine flatulence, bacteria in bogs and fossil fuel manufacture. Almost in all parts of the world, rice is grown on flooded fields. When fields are flooded, anaerobic situation build up and the organic matter in the soil decays, releasing methane to the atmosphere. Nitrous oxide, which is a colourless gas with a sweet odour, is another green house gas. The main sources of nitrous oxide include nylon and nitric acid production, cars with catalytic converters, the use of fertilizers in agriculture and the burning of organic matter. Greater emissions of nitrous oxides in the recent decades is leading global warming

Another major cause of global warming is deforestation. Deforestation is to be blamed for 25% of all carbon dioxide release entering the atmosphere, by the cutting and burning of about 34 million acres of trees each year. Trees collect the CO2 that we breathe out and give away from various other sources, and they give back oxygen that we breathe in. Thus, cutting of trees is leading to greater concentration of carbon dioxide in the atmosphere. Greater urbanization, requirement of land for factories and buildings, requirement of timber are all reasons that are leading to deforestation, which in turn is leading to global warming.
These temperature increases are likely to result in an increased frequency and severity of weather events such as heat waves, storms and flooding. Rising levels of greenhouse gases in the atmosphere could set in motion large-scale changes in Earth’s natural systems. Some of these could be irreversible - the melting of large ice sheets will result in major consequences for low-lying areas throughout the world

Conclution:

Are the developing countries responsible for global warming?

To answer the above question the need to understand the concept of Global warming, its consequences, steps taken to curb global warming and the contribution of the developing nations towards the same. Developing countries including China and India were asked to set voluntary targets for greenhouse gas emissions. Contribution of the developing nations: The US and Australia have refused to ratify the Kyoto protocol, arguing it would damage their economy. Developing countries also argue that they should not be denied the right to develop their economies, which inevitably means an increase in energy consumption. They also say that the burden of responsibility for current climate change lies with developed nations, whose industrial activities over the past century are largely blamed for increasing concentrations of greenhouse gases in the atmosphere. The question today is: Are only the developing countries responsible for global warming?

Golub Natalia.