A Brief Overview of Climate Change

Apon Zahir | 11 October 2021
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Whenever we hear or read about Climate change and the dangers it presents, it is a common tendency among city dwellers to think of it as a distant and foreign danger. When compared to the issues we face day to day, whether that be a global pandemic, dysfunctional traffic, corruption in private and public institutions, etc, the issue of climate change always tends to take a back seat. However, one just has to see the weather outside to realize that this issue has been knocking on our front door for some time now. Arbitrary downpours, an increase in floodings and natural disasters, and a gradual shift in the seasonal cycles with longer summers and shorter winters; all clear and present indications that something is awry in this part of the world. The question now is what can we do about it? 

The theory behind climate change is simple. Many of us even read about it in high school. According to NASA, Scientists attribute the global warming trend observed since the mid-20th century to the human expansion of the "greenhouse effect" — warming that results when the atmosphere traps heat radiating from Earth toward space.

Certain gases in the atmosphere block heat from escaping. Long-lived gases that remain semi-permanently in the atmosphere and do not respond physically or chemically to changes in temperature are described as "forcing" climate change. Gases, such as water vapour, which respond physically or chemically to changes in temperature are seen as "feedbacks" (NASA 2021).

Gases that contribute to the greenhouse effect include:

-    Water Vapour

-    Carbon dioxide (CO2)

-    Methane

-    Nitrous Oxide

-    Chlorofluorocarbons (CFCs)

Human activities (primarily the burning of fossil fuels) have fundamentally increased the concentration of greenhouse gases in Earth’s atmosphere, warming the planet. Natural drivers, without human intervention, would push our planet toward a cooling period (NASA 2021). 

A changing climate leads to changes in the frequency, intensity, spatial extent, duration, and timing of weather and climate extremes, and can result in unprecedented extremes. Scientific models predict a significant increase in temperature extremes by the end of the twenty-first century. In many parts of the world, the frequency of heavy precipitation or the fraction of total rainfall from heavy rains is expected to rise. 

Mean sea-level rise is extremely likely to contribute to future increases in extreme coastal high water levels. Droughts are expected to worsen in some seasons and locations owing to decreased precipitation and/or increased evapotranspiration. 

Changes in heat waves, glacial retreat, and/or permafrost degradation are expected to have a significant impact on high-mountain phenomena such as slope instabilities, mass movements, and glacial lake outburst floods. There is also a significant likelihood that changes in heavy precipitation will have an impact on landslides in some areas. 

The low elevation of small island states and coastal regions make them particularly vulnerable to rising sea levels and impacts such as inundation, shoreline change, and saltwater intrusion into underground aquifers (Seneviratne 2012).

Modern industrial civilization, as we have built it over the last 150 years, is fundamentally harmful to the environment. Whatever we do to make our lives simpler, safer, and more comfortable harms the biosphere. The food we eat, the streets we travel on, the clothing we wear, the devices we use, how we move, and the pleasant temperature we artificially generate around us; all leads to increasing the concentration of greenhouse gasses (Kurzgesagt 2021).

The Culprits

We must cut global greenhouse gas emissions quickly if we are to avoid severe climate change. Every year, the world emits about 50 billion tonnes of greenhouse gases. We must first understand where our emissions come from to determine how we can most effectively cut emissions and what emissions can and cannot be removed with existing technologies.  

By far the largest emitter of greenhouse gases, Asia accounts for 53% of worldwide emissions. However, because Asia is home to 60% of the world's population, per capita emissions in Asia are somewhat lower than the global average. China is Asia's and the world's largest emitter by a considerable margin: it emits about 10 billion tonnes per year, accounting for more than a quarter of global emissions. North America, which is led by the United States, is the second-largest emitter, accounting for 18% of world emissions. It is closely followed by Europe, which emits 17 per cent. Africa and South America are both minor emitters, each contributing to 3–4% of world emissions. (Ritchie and Roser 2020).

The figure above shows the breakdown of global greenhouse gas emissions in 2016. The overall picture you see from this diagram is that almost three-quarters of emissions come from energy use; almost one-fifth from agriculture and land use  [this increases to one-quarter when we consider the food system as a whole – including processing, packaging, transport and retail]; and the remaining 8% from industry and waste (Ritchie and Roser 2020).

Income or regional group

Share of population (%)

Share of production-based CO₂ emissions (%)

Share of consumption-based CO₂ emissions (%)

High income




Upper-middle income




Lower-middle income




Low income




North America








Latin America & the Caribbean
















The richest (high and upper-middle-income) nations in the world accounted for half of the world's population but 86% of emissions, according to the study. We find the same result on a consumption basis, but this is because upper-middle-income nations predominantly export emissions to high-income nations. When corrected for trade, high-income nations' emissions rise from 39 to 46% (despite having only 16% of the population); upper-middle-income nations' emissions fall by the same amount (7 percentage points) from 48 to 41%. Overall, this balances out in the top half of the world population: upper-middle-income nations are net exporters, while high-income nations are net importers.

In the bottom half, it appears that very little changes for the collective of lower-middle and low-income nations: their production and consumption emissions shares are effectively the same.

By region, we see that traded emissions tend to flow from Asia to North America and Europe (Asia’s share reduces when adjusted for trade whilst North America and Europe’s share increases).

Collectively, nations without consumption-based estimates due to poor data availability account for approximately 3 per cent of global emissions. Many of the missing nations are at low and lower-middle incomes. With the addition of these nations, we would expect small percentage point shifts across the distribution. 

On a consumption basis, high-income nations (Europe and North America in particular) account for an even larger share of global emissions (46 per cent — nearly three times their population share of 16 per cent) (Ritchie and Roser 2020).

The Victims

There is clear evidence as seen above that the economic activities of the developed and developing nations such as China, USA are responsible for the bulk of greenhouse gas emissions. However, the victims of their actions are some of the least developed nations in the world, who have neither the financial nor the technical capability to deal with the consequences of climate change. 

The Climate Vulnerable Forum (CVF) is an international partnership of countries highly vulnerable to a warming planet. The Forum serves as a South-South cooperation platform for participating governments to The CVF is the international forum for countries most threatened by climate change. Composed of 48 members from Africa, Asia, the Caribbean, Latin America and the Pacific, it represents some 1.2 billion people worldwide. It was founded in November 2009 by the Maldives at Male’, together with 10 other countries. The Forum is led by a rotating chair for an ordinary period of two years, with Bangladesh currently chairing for the second time for the period 2020-2022.act together to deal with global climate change. (CVF 2021)

In 2015, the twenty member countries in a forum chaired by the Philippines launched the official bloc of the forum, the 'V20' or 'Vulnerable Twenty', consisting of the top 20 nations from all over the world that are most affected by the catastrophes rooted from climate change. The members of the bloc are Afghanistan, Bangladesh, Barbados, Bhutan, Costa Rica, Ethiopia, Ghana, Kenya, Kiribati, Madagascar, Maldives, Nepal, Philippines, Rwanda, Saint Lucia, Tanzania, Timor-Leste, Tuvalu, Vanuatu and Vietnam. During the 2nd V20 Ministerial Dialogue in April 2016 in Washington DC, the V20 recognized the 23 new members that joined the CVF in 2015 as incoming members in the V20 initiative. Combined, the underdeveloped nations of the V-20 contribute to around only 2.5% of the world’s GDP. (V-20 2021)

Uniting the World to Fight Climate Change

It is clear now that those who are more vulnerable to the effects of climate change are not the ones responsible for exaggerating the condition, neither are they capable of protecting themselves. The actions of individuals are not enough to curb the course of climate change. It will take the whole world to unite and pool together their resources and combined knowledge and ingenuity to ensure our planet remains habitable for future generations.  

The UNFCCC secretariat (UN Climate Change) is the United Nations entity tasked with supporting the global response to the threat of climate change. UNFCCC stands for United Nations Framework Convention on Climate Change. The secretariat was established in 1992 when countries adopted the UNFCCC. The original secretariat was in Geneva. Since 1995, the secretariat has been located in Bonn, Germany. The Convention has near-universal membership (197 Parties) and is the parent treaty of the 2015 Paris Agreement. The main aim of the Paris Agreement is to keep the global average temperature rise this century as close as possible to 1.5 degrees Celsius above pre-industrial levels. The UNFCCC is also the parent treaty of the 1997 Kyoto Protocol. The ultimate objective of all three agreements under the UNFCCC is to stabilize greenhouse gas concentrations in the atmosphere at a level that will prevent dangerous human interference with the climate system, in a time frame that allows ecosystems to adapt naturally and enables sustainable development.

Focussing in its early years largely on facilitating the intergovernmental climate change negotiations, the secretariat today supports a complex architecture of bodies that serve to advance the implementation of the Convention, the Kyoto Protocol and the Paris Agreement.

The secretariat provides technical expertise and assists in the analysis and review of climate change information reported by Parties and in the implementation of the Kyoto mechanisms. It also maintains the registry for Nationally Determined Contributions (NDC) established under the Paris Agreement, a key aspect of the implementation of the Paris Agreement.

The secretariat organizes and supports between two and four negotiating sessions each year. The largest and most important is the Conference of the Parties, held annually and hosted in different locations around the globe. It is the largest annual United Nations conference, attended on average by around 25,000 participants. In addition to these major conferences, the secretariat organizes annual sessions of the so-called subsidiary bodies as well as a large number of meetings and workshops throughout the year (UNFCCC 2021).

Cop26 is the 2021 edition of the united nations annual climate change conference. COP stands for Conference of the Parties. Parties are the signatories of the United Nations Framework Convention on Climate Change (UNFCCC) - a treaty agreed in 1994 which has 197 Parties (196 countries and the EU). The 2021 conference, hosted by the UK, in partnership with Italy, in Glasgow, will be the 26th meeting of the Parties, which is why it's called COP26. United Nations climate change conferences are among the largest international meetings in the world. The negotiations between governments are complex and involve officials from every country in the world as well as representatives from civil society and the global news media. (UKCOP26 2021)

One of the most important outcomes of this global cooperation was the Paris Agreement, which was agreed upon at COP21 in 2015. For the first time, it saw almost every country around the world enter into a legally binding commitment to reduce emissions. It was ‘top down’ in that every country – no matter how big or small – signed up to cutting carbon emissions to limit global warming to well below 2 degrees and ideally to 1.5 degrees above preindustrial levels, and it was ‘bottom up’ in that it left room for each country to decide how they would get there. These were called Nationally Determined Contributions (NDCs). The Paris Agreement also set out ambitious goals on adaptation and finance, recognising that many people around the world are already experiencing the impacts of a changing climate and that support - financial, technical and capacity building - would be needed.


CVF. 2021. "About." CVF website. https://thecvf.org/about/.

Kurzgesagt. 2021. Can YOU Fix Climate Change? [Video]. September 22. https://www.youtube.com/watch?v=yiw6_JakZFc.

NASA. 2021. "The Causes of Climate Change." NASA. September 28. Accessed October 5, 2021. https://climate.nasa.gov/causes/.

Ritchie, Hannah, and Max Roser. 2020. "CO₂ and Greenhouse Gas Emissions." OurWorldInData.org. Accessed October 5, 2021. https://ourworldindata.org/co2-emissions#per-capita-co2-emissions.

Seneviratne, S.I., N. Nicholls, et al. 2012. "Changes in Climate Extremes and their Impacts on the Natural Physical Environment." A Special Report of Working Groups I and II of the Intergovernmental Panel on Climate Change (IPCC) (Cambridge University Press) 109-230.

UKCOP26. 2021. "CPO26 Explained." ukcop26.org. https://ukcop26.org/wp-content/uploads/2021/07/COP26-Explained.pdf.

UNFCCC. 2021. "About Us." unfccc.int. Accessed October 5, 2021. https://unfccc.int/about-us/about-the-secretariat.

V-20. 2021. "Members." V-20. https://www.v-20.org/members.

Apon Zahir is a Research Intern at Centre for Governance Studies 

Views in this article are author’s own and do not necessarily reflect CGS policy.