Greenhouse effect, a global threat

From a physical phenomenon, the greenhouse effect has led to a terrible consequence causing bad climate change on earth, awakening the anxiety of all mankind and every country on different continents.

Global concerns

That is why this year's Climate Change Summit, which took place in the past few days in New York (USA), was more crowded than ever with the presence of senior government leaders from 120 countries and representatives of 200 multinational corporations and companies.

UN Secretary-General Ban Ki-moon speaks at the UN Climate Change Summit in New York. Photo: Reuters.

And it was more heated than ever when in many major cities around the world, from New York (USA) to Paris (France), from London (UK) to Sydney (Australia) etc., there were 2,000 massive demonstrations with 600,000 participants. Even the Secretary General of the United Nations, Ban Ki-Moon, also took to the streets. Everyone turned to, first of all, the politicians leading the countries, the big bosses of international corporations. They must be responsible and must act to avoid for humanity the danger of the "greenhouse effect", of climate change; which, according to Mr. Ban Ki-Moon, is a "flaw of the times". And according to the Secretary General of the United Nations, every person living on this Earth must also be responsible for the increase in greenhouse gas emissions, participating in aggravating the dangers of the "greenhouse effect".

By now, perhaps everyone should know more clearly the concept of the greenhouse effect, its dangers and from there see the need to contribute to immediately stopping the increase in greenhouse gas emissions.

The danger of "greenhouse"

The concept of the greenhouse effect is most easily understood in the specific case of a house that is completely sealed, with four sides and a roof made of transparent glass. We can take the example of a flower garden in the cold region of Da Lat. Here, due to the radiation of sunlight penetrating through the glass walls and roof, the heat of sunlight is absorbed by the air mass in the house and warms the entire space, not just in the places that are directly illuminated, and this heat is kept inside for a long time. The phenomenon of absorbing and keeping heat like that is absolutely correct when called the greenhouse effect.

This concept can be extended to the Earth today when the atmosphere of our planet is covered by a special layer of gas. For this “house” Earth, in terms of heat transfer, the “glass layer” is made up of carbon dioxide gas molecules CO2 or other gases, also emitted by humans: CO2, CFC, CH4, O3, NO2… and water vapor; arranged in order of decreasing impact causing the greenhouse effect.

This special “glass layer” does not prevent sunlight (mainly shortwave radiation or ultraviolet rays) from penetrating and shining on the Earth's surface, but prevents reflected light (mainly longwave radiation or infrared rays) from escaping into the atmosphere after the sunlight is partially absorbed by the Earth and the remaining part is reflected back into space.

Illustrate the role of the greenhouse effect in affecting the Earth's surface temperature.

Thus, CO2 and the above greenhouse gases have the effect of retaining the heat of the Sun, not allowing it to reflect into space. If greenhouse gases exist in moderate concentrations, they help keep the Earth's temperature from getting too cold, but if the concentration is as high as it is now, the consequence is that the atmosphere and the surface of the Earth will heat up. In fact, the current concentration of carbon dioxide CO2 is about 0.036%, causing the Earth's temperature to increase to about 30°C. But without the above greenhouse gases, the temperature would drop to about -15°C.

Obviously, it is the greenhouse gases emitted by humans, through the greenhouse effect, that have increased the Earth's temperature to the point that global climate change is increasingly affecting human life. With that increase, the level of danger will come to a point where it threatens the lives of hundreds of millions of people, if not the survival of humanity.

In the immediate future, the effects of climate change are being felt in many ways.

For example, impacts on water resources lead to shortages of drinking water, water for agriculture (for irrigation, aquaculture, etc.), for industry (for hydroelectric power, etc.), and for forestry (forest fires, etc.).

For the ecosystem, global warming changes the normal living conditions of organisms (many species have their living areas reduced or become extinct...) and threatens human health (human health declines, many new diseases appear, epidemics spread...)

In particular, at some point, if the Earth's temperature is high enough, it can melt the ice in the Arctic and Antarctic rapidly, causing sea levels to rise too high, possibly leading to a flood. For example, in the United States, sea levels are expected to rise 50 cm by 2100, which could wipe out 5,000 square miles of dry land and 4,000 square miles of wet land.

Join hands to save the Earth

The atmosphere inside and outside the Climate Change Summit this year in New York has proven that the Earth is truly entering a period of danger with the increase of greenhouse gas emissions, mainly carbon dioxide CO2. And it is also time for all countries and all people to take action and join hands to save the Earth.

The UN Secretary General at the 2014 New York Conference issued a call: "To get through this storm, we need the cooperation of all countries. We have never faced a similar challenge." And the previous goal of keeping global temperature from rising more than 2 degrees Celsius was reiterated by him and affirmed as an important part of action programs against climate change.

By declaration, by policy or by concrete implementation, most countries have shown that they are ready to save the Earth, that is, to save their country, to save humanity, that is, to save their people, themselves and their future generations.

At the New York Summit last September, governments agreed in principle to expand the use of renewable energy, nuclear power and increase support for developing countries in their efforts to slow global warming.

And in fact, some countries, for example, the Nordic countries, Germany, Spain, etc. have shifted their investment to wind and solar power, despite the high cost. Countries like France, the US, and South Korea maintain or add new nuclear power plants. Many countries like India, Poland, China, newly developed countries in the Middle East, Southeast Asia, and even Africa have chosen the path of developing nuclear power and gradually reducing coal power.

Nuclear power plants – the “nemesis” of global climate change threats. Photo: Source www.ecofriend.org.

On the other hand, the heads of state also set the target of stopping deforestation, increasing food production and increasing the use of electric vehicles in cities by 30% by 2030.

Not only governments, businesses also agree to invest in the “low carbon emission” economy. The total investment of countries and businesses is up to 200 billion dollars from now until 2015. Some cities are contributing up to 70% of the greenhouse effect such as New York, Paris, Johannesburg, Seoul and many other large cities have made agreements to reduce CO2 emissions.

Clearly, the New York Summit in September 2014 has sent out encouraging signals for the cause of saving the Earth from the danger of climate change.

However, there are still many concerns. Many large countries, important countries in the fight against climate change, still do not send their highest-ranking officials to the Conference. Especially, the Conference has passed but there is still a lack of an international agreement capable of setting criteria, specific steps with the division of responsibilities for each country, etc.

However, it should also be understood that this is only a preparatory Summit to create more political momentum, promote the negotiation process within the framework of member countries of the United Nations Framework Convention on Climate Change (UNFCCC), and prepare for the next Summit in Lima later this year.

And it is hoped that meaningful legal agreements will be reached at the subsequent UNFCCC Conference of the Parties, in Paris, in 2015.

According to Vietnamnet