Impacts and Adaptation on Climate Change


The Earth’s Climate System

The climate system is a complex system. Climate change and variation is due to the interaction exchange of matter and energy


Weather and Climate

Meanings and differences between “Weather” and “Climate”


Climate Change

Definition, Cause of climate change, and Source of GHG

The Earth’s Climate System

The Earth’s Climate System

The climate system is a complex system. Climate change and variation is caused by interaction and exchange of matter and energy between the five global system components; Atmosphere (air), Hydrosphere (oceans, lakes, rivers), Biosphere (living things), Cryosphere (snow and ice) and Lithosphere (soils and rocks) which is effected by both internal variability and external forcing such as the solar cycle, changing the Earth’s orbit, volcanic eruption and energy transfer etc. Maintaining energy balance affects long-term change and variability of the Earth’s climate system as shown in Figure 5-1.
Figure 5-1 The Earth’s Climate System

Climate system, Earth's energy budget and Climate change

Earth’s energy budget accounts for the balance between the energy that Earth receives from the Sun, and the energy the Earth radiates back into outer space after having been distributed throughout the five components of Earth’s climate system. When the total of incoming energy is greater than the outgoing energy, Earth’s energy budget is positive and the climate system is warming. If more energy goes out, the energy budget is negative and Earth experiences cooling. Thus any changes to the Earth’s climate system that affect how much energy enters or leaves the system alters Earth’s radiative equilibrium and can force temperatures to rise or fall. The natural climate forces related to climate system are included;

The “Milankovitch Cycle” is a cyclical movement related to the Earth’s orbit around the sun. It is an important astronomical factor that causes changes to the Earth’s axis of rotation, the swing of the Earth’s axis and the orbit of the Earth around the sun. This causes the Earth to be close to or away from the sun, strongly influenced climatic patterns on Earth either during the higher or lower than normal global temperatures. This phenomenon occurs in cycles every 10,000 – 20,000 years. (Atsamon Limsakul, Kansri Boonpragob and Amnat Chidthaisong, 2011: 5) (Figure 5-2).

The “Albedo” is the portion of energy from the Sun that is reflected by the earth’s surface, the Earth’s surface is covered by many landcover types and related to diffused reflection of solar radiation back into the atmosphere such as clouds and ice sheets which are white, thereby Hight Albedo is capable of reflecting the sun rays back into the atmosphere well, the ground and forests are dark, thereby Low Albedo has the ability to absorb radiation from the sun. Consequently, the proportion of the material covering each area is an important mechanism for controlling the reflection of the sun’s rays and temperature of the Earth (Figure 5-3). It is also linked to solar radiation absorption and reflection into the atmosphere, which is incoming radiation is short-wave radiation when it hits the earth then transforms into heat energy or long wave radiation. If it can’t be reflected back into the atmosphere, it will cause accumulation of heat energy around the earth’s surface resulting in global temperatures rising, including other changes in the climate system (Figure 5-4).

The Earth’s Climate System and Climate Change

Weather and Climate

“Weather” and “Climate” have different meanings as follows:

Weather phenomena refers to the atmospheric conditions that occur in a short period of time, such as weather for 3 hours, 1 day, 2 weeks, or occurrences of no more than 1 month. Meteorological measurements include temperature, humidity, air pressure, clouds, wind and rain. In contrast, Climate, sometimes understood as the “average weather,” is defined as the measurement of the mean and variability of relevant quantities of certain variables (such as temperature, precipitation or wind) over a period of time, ranging from months to thousands or millions of years, ranging from months to thousands or millions of years. The classical period is 30 years, as defined by the World Meteorological Organization (WMO). Climate in a wider sense is the state, including a statistical description, of the climate system. The weather and climate that occurs at local, regional and global scales are closely link
Kansri Boonprakob, 2010. Basic knowledge about climate change models in Thailand climate change information volume 2: climate model and future climate. The Thailand Research Fund. [Amnat Chidthaisong (Author)] – WMO, FAQs – Climate,

Climate Change

Definition of Climate Change

“Climate change” is defined differently but the academic definition accepted and referenced is the definition of the Intergovernmental Panel on Climate Change (IPCC) and the United Nations Framework Convention on Climate Change (UNFCCC). Climate change in IPCC usage refers to “a change in the state of the climate that can be identified (e.g. using statistical tests) by changes in the mean and/or the variability of its properties, and that persists for an extended period, typically decades or longer. It refers to any change in climate over time, whether due to natural variability or as a result of human activity” The UNFCCC defines climate change as “a change of climate that is attributed directly or indirectly to human activity that alters the composition of the global atmosphere and which is in addition to natural climate variability observed over comparable time periods.” It can be concluded that climate change means change of climate due to both short-term and long-term changes and natural fluctuations.

Causes of climate change

Climate change is caused by “increasing levels of greenhouse gases in the atmosphere” as a result of anthropogenic causes, especially after the industrial revolution (18th century) during which the atmosphere accumulated high levels of greenhouse gases, causing an imbalance and the “greenhouse effect” thereby resulting in climate change or global warming. This resulted in changes to other parts of the global climate system, including changes in meteorological variables
IPCC, 2007: Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change [Solomon, S., D. Qin, M. Manning, Z. Chen, M. Marquis, K. B. Averyt, M. Tignor and H. L. Miller (deds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA. .
Figure 5-5 Causes and effects of greenhouse effect

Greenhouse Gases and Sources

Greenhouse gases are gases in the atmosphere that can absorb some of the Earth’s outgoing heat radiation and reradiate it back towards the surface, thus contributing to the “greenhouse effect”, Greenhouse gases have a profound effect on the energy budget of the Earth system which, if balanced, will maintain the surface temperature from a sudden change resulting in a warm and suitable temperature for the existence of life.

During the 18th Session of the Meeting of the Parties to the Kyoto Protocol 2012 in Doha, the Parties classified anthropogenic greenhouse gas emissions into 7 types, including:

  1. Carbon dioxide(CO2)
  2. Methane (CH4)
  3. Nitrous oxide (N20)
  4. Hydrofluorocarbons (HFCs)
  5. Perfluorocarbons (PFC)
  6. Sulphur hexafluoride (SF6)
  7. Nitrogen trifluoride (NF3)

Each greenhouse gas has its origin as follows:

  1. Carbon dioxide (CO2) generally has a natural source from volcanic activity and degradation of organic matter. But nowadays, human activities are the main factors in creating and releasing carbon dioxide such as fuels and fossils combustion etc.
  2. Methane (CH4) is a gas produced by decomposing waste in nature, but 60% of methane in the atmosphere is caused by human activities such as landfill waste disposal, burning wood fuel and agriculture etc.
  3. Nitrous oxide (N2O) is naturally sourced from bacteria, both soil and oceanic bacteria including the degradation of organic matter and sources of human activities such as industry production process, energy generation and consumption, agriculture and livestock, the burning of agricultural waste and various fuels.
  4. Hydrofluorocarbons (HFCs) are frequently used in air conditioning and refrigerants.
  5. Perfluorocarbons (PFCs) are another type of refrigerant.
  6. Sulphur hexafluoride (SF6) is a gas contained in an electrical control in transmittances system and electrical distributing devices for use as an electrical insulator preventing sparks from high voltage electrical equipment or helps to ventilate heat from high voltage electrical equipment.
  7. Nitrogen trifluoride (NF3) is a gas used in the production of electronic devices or circuits for computers.
In 2014, the IPCC reported direct and indirect greenhouse gas emission sources by classifying the source according to the economic sector and found that the electricity and heat generation industries have proportions of greenhouse gas emissions similar to agriculture, forestry and land-use sector but more than transport sector as shown in Figure 5-6. However, each greenhouse gas has an age range in the atmosphere and potential to cause global warming differently as shown in Table 5-1.
Figure 5-6 Greenhouse gas emissions by economic sectors (IPCC, 2014).
Table 5-1 Atmospheric lifetime and Global Warming Potential (GWP) relative to CO2 at different time horizons for various greenhouse gases
No. Gas name Lifetime (years) GWP relative to CO2 for given time horizons
20-year 100-year
1 Carbon dioxide(CO2) * 1 1
2 Methane (CH4) 12.4 84 28
3 Nitrous oxide (N20) 121 264 265
4 Hydrofluorocarbons (HFCs) 2 วัน – 800 < 1 – 15,000 < 1 – 12,400
5 Perfluorocarbons (PFC) 1.1 วัน – 50,000 < 1 – 8,210 < 1 – 11,100
6 Sulphur hexafluoride(SF6) 3,200 17,500 23,500
7 Nitrogen trifluoride(NF3) 500 12,800 16,100
*No single lifetime can be given. See also Supplementary Material Section 8SM “Anthropogenic and Natural Radiative Forcing” 8.SM.11. See more details in Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change, Joos et at. (2013).
Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Chang

Greenhouse gases concentration in the atmosphere

  According to the IPCC-WG’s AR5, during the period from Industrial Revolution to present (1890 – 2014), there were increasing concentrations of greenhouse gases in the atmosphere caused by human activities with long-term predictions that the concentration of carbon dioxide in the atmosphere in the year 2100 will increase to 550-800 part per million (ppm) as shown in Figure 5-7. However, the concentration of carbon dioxide in the atmosphere will vary according to industries and world economy. The highest monthly average carbon dioxide concentration measurement at the Mauna Loa Station, Hawaii, The United States is 414.7 ppm (data as of May 2019), which is the highest detected in 61 years and which conform to long-term forecasts.

Figure 5-7 The tendency of changes in carbon dioxide concentration in the atmosphere.
  1. IPCC, 2013: Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernment Panel on Climate Change [Stocker, T.F., D. Qin, G.-K. Plattner, M. Tignor, S.K. Allen, J. Boschung, A. Nauels, Y. Xia, V. Bex and P.M. Midgley (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, 1535 pp.
  2. National Oceanic and Atmospheric Administration (2019). Carbon dioxide levels hit record peak in May. Retrieved December 9, 2019, from
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