What is Global Warming (Definition, Phenomenon, Causes, Evidence, Problems, Efforts to Improve)

Learn about global warming: definition, phenomenon, causes, evidence, problems, and efforts to improve it!

 

Korea, a country with four distinct seasons, is experiencing an unusual climate phenomenon of shorter spring and fall and extreme heat and cold. Many scientists interpret this as the effects of global warming caused by increased greenhouse gas emissions due to industrialization. Today, global warming has become a familiar word to people of all ages due to the influence of various media such as education, movies, and news. Climate change and global warming are high on the political agenda today. In this article, we will clarify what global warming is, what it is, and what causes it, examine the evidence of global warming from the past to the present, the problems and efforts to improve it, and finally, the future of global warming.
Global warming is the “long-term increase in the temperature of the Earth’s near-surface environment. The warming being discussed today refers to the increase in temperature since the 1970s, and the increase in temperature since scientific weather observations began in the late 19th century. Observations from around the world show that global warming appears to be progressing slowly but surely. Glacier retreat, melting permafrost, ecosystem changes and crises, and more frequent extreme weather events are all reported as effects of warming.
Glaciers are shrinking all over the world. Growth and shrinkage is determined by the amount of ice melted and ice added, but it’s important to note that changes in climate are not always immediately reflected in glaciers. This is in contrast to things like sea ice, which can fluctuate from season to season and year to year. Studying glaciers can provide information about past climate fluctuations, even in areas that don’t have a weather network. In addition to glacier shrinkage, there are a number of other phenomena that are thought to be caused by warming. For example, the melting of Siberian permafrost has never been seen before. Permafrost is frozen soil that stays frozen year-round and covers about 20% of the Earth’s land mass, and it’s currently melting and disintegrating.
Along with shrinking glaciers, the Arctic is often referred to as the frontline of warming, the first place to be affected by global warming. The average annual sea ice extent of the Arctic Ocean was about 13 million square kilometers in 1950, about 60 times the size of the Korean Peninsula, but has decreased by about 2.5 million square kilometers in the last decade. Shrinking ice in the Arctic Ocean has the potential to alter ocean currents and affect climate on a global scale, and it will also affect the ecosystems of the Arctic Ocean. In addition to melting ice in the polar regions, climate change, which is believed to be an effect of warming, is occurring in other parts of the world. In East Africa, millions of people are facing starvation due to frequent droughts, and in Europe, a heat wave hit in 2003, killing more than 10,000 people in France alone. Forest fires, hurricanes like Katrina, which caused the worst flooding on record, flooding, and rising sea levels are other examples of climate change caused by global warming.
In 2007, the Intergovernmental Panel on Climate Change (IPCC) compiled its latest report on the scientific facts, impacts, and responses to global warming. The IPCC was established by the United Nations Environment Programme (UNEP) and the World Meteorological Organization (WMO) to compile the findings of climate change research reported by scientists around the world. The Fourth Assessment Report was released six years after the Third Assessment Report in 2001. The Fourth Report states that ‘warming is occurring at a rate of 0.74℃ per century. This is more than the “0.6℃ per century” claimed in the Third Report. “These trends indicate that the rate of warming has accelerated since the 20th century,” the fourth report said. It also reported that “global sea levels rose 17 centimeters in the 20th century. There is still no scientific evidence to simply link individual weather events to global warming, such as Hurricane Katrina in the United States in 2005 or the heat wave in Europe in 2003. However, the IPCC’s Fourth Assessment Report indicates that future global warming is likely to increase the frequency of heat waves, heavy rainfall, and droughts.
We’ve established that global warming is definitely happening, but what is causing it? The number one factor influencing the Earth’s surface temperature is, of course, the source of heat: the sun. Since the Earth doesn’t absorb all of the sun’s radiation, its reflectivity is also an important factor in the Earth’s surface temperature. French mathematician Georges Fourier thought that the reason the Earth is actually warm is because the atmosphere is absorbing radiation that would otherwise escape into space. This was the discovery of the ‘greenhouse effect’. Earth has an atmosphere, and it contains greenhouse gases such as carbon dioxide. Greenhouse gases do not absorb visible light from the sun, but they do absorb infrared radiation from the earth. They then re-radiate this infrared radiation in all directions. This re-radiation further warms the Earth’s surface. Based on this mechanism, there are three suspected causes of global warming. The first is the possibility of increased solar radiation, the second is the possibility of decreased reflectivity, and the third is the possibility of increased greenhouse effect.
Changes in the Earth’s position relative to the Sun cause the amount of solar radiation to fluctuate. The Earth’s orbit around the Sun is not a constant ellipse, but is deformed by the gravitational influence of Jupiter and other bodies. Serbian astronomer Milutin Milanović believed that the tilt and orientation of the Earth’s axis of rotation, each with a period of tens of thousands of years, would cause complex fluctuations in the amount of solar radiation reaching the Earth. These periodic fluctuations are called “Milankovitch cycles. Volcanic activity and the presence of snow and ice increase the reflectivity of the sun’s light, and there are other natural, non-human factors that cause global temperatures to fluctuate.
In addition to changes in solar radiation and reflectivity caused by natural phenomena, there are also changes in the greenhouse effect. Gases such as water vapor, carbon dioxide, and methane can absorb energy from infrared radiation, and these gases are now called “greenhouse gases”. When they receive electromagnetic waves, the bond lengths of their molecules change, causing them to vibrate and generate heat. The only electromagnetic waves that can cause these vibrations are infrared. Only the bonds connecting different types of atoms change length when bathed in infrared light, which is why nitrogen and oxygen are not greenhouse gases.
The concentration of carbon dioxide is about 35% higher than it was before the Industrial Revolution. At the end of 1994, nature absorbed about 3 billion tons of carbon dioxide per year. And since humans emit 6.4 billion tons of carbon dioxide per year, 3.4 billion tons remain in the atmosphere each year. From these findings, many scientists have made it clear that human activity, represented by the use of fossil fuels, is responsible for the current rise in carbon dioxide concentrations. Of the three factors suspected of causing global warming, the computer-reproduced graphs match the observed patterns very well over the 20th century, when adding in the factors caused by human activity, including the rise in greenhouse gases, including carbon dioxide. The IPCC’s Fourth Assessment Report synthesized these findings and made the following conclusions about the causes of current global warming ‘Climate change up to 1950 can be attributed, with a probability of more than 66%, to changes in volcanic activity and solar radiation. However, the observed increase in global average temperature since the mid-20th century can be attributed with more than 90% probability to an increase in greenhouse gases from human activities.
Thermometer records have only been available since around 1850. The only clues we have to past climate on the scale of hundreds of millions of years are fossils. For temperatures on the scale of hundreds of thousands of years, the thick ice covering Antarctica or Greenland is a clue. So far, we know that over the past 500,000 years, there have been about five warm and five cold periods. The cold periods, called glacial periods, and the warm periods, called interglacial periods, have repeated more or less in line with the Milankovitch cycle mentioned earlier. The nearest ice age ended about 20,000 years ago. The Earth then warmed by about 5 degrees, and the current interglacial period began about 10,000 years ago. For the past 10,000 years, the Earth’s temperature has been relatively stable, and it was against this backdrop of a stable climate that humans have grown and developed various civilizations.
On a time scale of 1000 years, we examine the width of the rings left on trees as a clue. This is because temperature and insolation are important factors in determining how much a tree grows in a year. Taken together, the various analyses show that the past 1300 years have seen one mild warm period and one mild cold period. The analysis also indicates that the current period is the warmest in the past 1300 years. Warmer periods than this have occurred many times in the past. Nevertheless, what makes the current global warming problematic? The biggest reason is the rate of warming. The warming from the glacial to interglacial periods was about 0.1°C per century, even though it was large. However, according to the IPCC’s Fourth Assessment Report, the current rate of warming is 1.74°C per century. The current warming is happening at a rate that has never been seen in the past.
In the previous section, we looked at the localized effects of global warming. Along with increasing global temperatures, the effects of global warming include sea level rise, changes in precipitation amounts and patterns, and the expansion of subtropical desert regions. Global warming also includes the shrinking of the Arctic and the reduction of persistent glaciers, permafrost, and sea ice. Reports of increased weather extremes and heat waves, droughts and heavy rainfall, ocean acidification and species extinction are often cited as examples of global warming. The effects of global warming on human life include decreased agricultural yields and the creation of climate change refugees. In addition, rising sea levels will be the biggest disaster for human life. If the temperature rises by 3℃, most of the glaciers in the Arctic will melt into floating icebergs, which will have no significant effect on sea levels, but in Antarctica, the melting of continental glaciers is expected to raise sea levels by about 7 meters. While only about 3% of each continent’s coastline would actually be under water, the catastrophe would be enormous, given that most of the world’s largest cities are built on the coast, and about a third of humanity lives in coastal areas.
The IPCC’s Fourth Assessment Report concludes that annual emissions of greenhouse gases can be stabilized at current levels by 2050 if we cut them in half from 2000 levels. In the 30 years since 1970, the world’s annual greenhouse gas emissions have increased by 70%. The Kyoto Protocol is the flagship international agreement to regulate and combat global warming. Adopted in December 1997 at the third Conference of the Parties to the United Nations Framework Convention on Climate Change in Kyoto, Japan, and officially entered into force on February 16, 2005, it sets greenhouse gas reduction rates for each country based on 1990 levels. Industrialized countries as a whole are required to reduce their emissions by at least 5%. The Kyoto Protocol also includes a mechanism for industrialized countries to provide financial and technical assistance to developing countries to cover a certain amount of their emissions reductions, and a mechanism for buying and selling emissions reductions. The money to cut greenhouse gases is spent on developing technologies that can contribute to reductions. However, since the United States, which accounts for 28% of global carbon dioxide emissions, withdrew from the agreement in March 2001 to protect its own industries, there are calls for a stronger international agreement. The IPCC’s Fourth Assessment Report cites biofuels and next-generation vehicles as effective means of reducing greenhouse gases in the transportation sector. It has only been in the last 30 years that human activity has become globally influential, and these issues are having a global impact.