Climate Change Questions We Should Be Asking

Climate change has become a household name, a catchphrase if you like. You hear it on the news every day, see it on your screen, or use your mobile phone to communicate with it. There is no escaping it.

Climate change is involved in every major calamity, such as hurricanes, extensive floods, wildfires, and volcanic eruptions.

You might have noticed that some of the younger generations are on the frontlines of the protests. Their most vocal and influential spokesperson is Greta Thunberg. They are advocating for their future. These young people are taking a stand on climate change because their generation will feel the impact.

You might say that the climate seems pretty normal. We get hot days, cold days, dry and wet seasons, and strong hurricanes occasionally. To think that these extreme events will not only happen soon but will increase in intensity and frequency, causing great devastation on the planet like never before, is quite absurd.

But what are the climate data and reports saying, and what have the experts and scientists been warning us about climate change?

Should we not listen to them and get to the bottom of things?

To have a clear understanding of climate change and all the terms associated with it, like global warming, carbon emissions, greenhouse gas, temperature rise and sea-level rise, these are the questions we need to ask:

What is global warming?

This means that the planet is getting hotter, caused by human activity.

The Earth’s temperature has indeed changed before. Still, the global warming we are experiencing now is a result of an increase in the average temperature of the Earth’s climate since the late 19th century, which is the start of the Industrial Revolution. The temperature has increased by 1 degree Celsius on average.

The following scientific institutions record this temperature increase: NASA, Met Office Hadley Centre, NOAA, and the Japanese Meteorological Agency. Their records go back to the late 19^th century.

Global warming is synonymous with climate change.  

Climate scientists have found that the cause of this warming, with overwhelming evidence, is human activity or how we put extra amounts of greenhouse gases (GHG) in the atmosphere by burning coal, natural gas, or oil for energy, also when we cut down forests that absorb carbon dioxide.

Greenhouse gases like carbon dioxide and methane trap heat on the Earth’s surface and prevent it from quickly escaping into space. We are adding more carbon and GHGS to the atmosphere every day, warming the planet.

The United Nations has convened the Intergovernmental Panel on Climate Change (IPCC) “to provide governments with scientific information that they can use to develop climate policies (About the IPCC, n.d.).”

So far, the IPCC has provided the most robust compilation of scientific data through the IPCC 5th assessment report, drawing from over 800 expert authors. The report projects that the temperature will rise at least 2 degrees Celsius by 2100, possibly up to 4 degrees Celsius or more.

What does 2 degrees Celsius mean?

Although this figure is tiny, scientists find it unacceptably high. A small increase in temperature will increase the chances of deadly heatwaves, droughts, flooding, and extinction. It will also increase sea levels as glaciers and sea ice melt. Further temperature increases will also affect the ability to grow food and the spread of diseases.

In 2018, the IPCC published another report comparing 2°C warming to 1.5°C warming. According to researchers, this half-degree difference in warming produces significant results. Fewer temperature increases mean fewer people will move from coastal areas, less severe natural events, and a lesser hit on the economy.

Limiting temperature increase below 1.5 or 2 degrees Celsius is quite impossible.

Fossil fuels provide over 80% of the world’s energy needs. We would need to replace fossil fuels with low-carbon and renewable sources like solar, wind, geothermal, nuclear, and carbon capture technology to reach zero emissions. Then, we would electrify everything. After that, we must still capture the remaining GHG directly from the air.

To target a 1.5°C temperature rise, we must cut our current emissions by half by 2030. This poses a huge technological and political challenge, and the global response is slow. Actions to reduce emissions are weak.

How do we know global warming is real?

Because of temperature measurements and data from various agencies worldwide, countries like the United States, Japan, and Europe have independent historical data showing that the Earth’s average temperature has risen by 0.8 degrees Celsius since the early 20^th century.

Other evidence by scientists includes:

• The melting of glaciers and ice sheets around the world,
• Satellite observation from 1970 showing warming in the lower atmosphere,
• More heat in the ocean, causing sea-level rise,
• Plants are flowering earlier in many parts of the world, and
• There is more humidity in the atmosphere.

The National Oceanic and Atmospheric Administration (NOAA) summarises global warming by these ten Indicators shown on the image below:

How do we know that humans are causing global warming?

Climate Scientists are more than 95% sure that it is humans who are causing global warming since 1950, because of the following reasons:

• Greenhouse gases like CO2, methane, and water vapour absorb infrared radiation and scatter it back to Earth. So the presence of gases prevents the heat from escaping back to space, trapping radiation that warms the planet’s surface.
• GHG concentrations in the atmosphere have grown significantly since the Industrial Revolution, directly linked to humans’ burning of fossil fuels.
• Satellite measurements also show that less infrared radiation escapes into space and instead returns to the Earth’s surface. This is strong evidence that the GHG effect is increasing.
• Simple climate models in the 1960s predicted that global warming caused by carbon dioxide in the atmosphere would cool the upper atmosphere because heat would be trapped in the lower layers. Satellite measurements later confirmed this.

How has global warming affected the world?

Data from the IPCC shows that every continent has experienced higher temperatures, and hot days are getting hotter.

As the world holds more moisture, heavier storms and floods occur. Hurricane Harvey’s record-setting rainfall is an example.

Over the past 50 years, heat waves have become longer and more frequent, particularly in Europe, Asia, and Australia.

Since the 1970s, glaciers and ice sheets worldwide have been shrinking, particularly those in Greenland and Antarctica.

Sea levels rose by 9.8 inches (25 centimetres) in the 19th and 20th centuries. The pace is speeding up due to thermal expansion caused by the warming of the oceans and melting glaciers and ice sheets.

A hotter climate can benefit crops in some high-latitude areas by lengthening the growing season, and CO2 increases photosynthesis. However, in other regions like California and tropical climates, it can damage crops and reduce yield by up to 40% by 2050.

Warmer winters result in declines in snow accumulations in the United States, which can increase flood, drought, and wildfire risk as water flows slowly over a season, and then all at once.

Debatable Impacts

To present a balanced picture of climate change, scientists are still debating whether some events can be linked to climate change. For example, droughts have become more frequent and intense in the American Southwest, Mediterranean Europe, and West Africa. Still, droughts have become less frequent in the Midwestern United States and Northwestern Australia. A recent study shows that the time between droughts has shortened globally, and areas affected by them take longer to recover.

Another is that hurricanes in the North Atlantic Ocean have become more intense since 1970; however, this does not show a global trend, particularly with tropical cyclones elsewhere.

What are the future impacts of global warming?

Depending on the temperature increase, a 4-degree Celsius increase will have a more dramatic effect than a 2-degree Celsius increase.

According to the IPCC, if global warming continues, it will create hotter temperatures, higher sea levels (between 0.6 and 6.6 feet), more severe heatwaves, droughts and floods, stronger hurricanes, a decline of crop yields, especially in the tropics, or an increase in some areas like the winter wheat in the United States, extinctions of many plants and animal species, and other long-term changes to the planet.

What do climate models say about warming that could happen in the coming decades?

The IPCC presents various scenarios of what could happen in the future depending on the concentrations of Greenhouse gases in the atmosphere. These scenarios are called Representative Concentration Pathways (RCP).

The first scenario is the RCP 2.6. This has the lowest GHG concentration as it assumes a decline in oil use, a population of 9 billion by 2100, increased energy efficiency, and steady emissions until 2020. It will decline and go negative by 2010. This is the most optimistic scenario of all. This will result in a temperature increase of below 2 degrees Celsius.

The next scenario is RCP 4.5, which relies on ambitious emissions reductions but expects emissions to decrease by 2040 and stay steady until 2100. In this scenario, a global temperature rise of over 3 degrees Celsius is expected.

RCP 6 expects an up to 75% increase from current emissions, which will peak and decline by 2060 as the world still burns fossil fuels. This will increase global temperature by over 4 degrees Celsius.

RCP 8.5 shows the highest emissions and the most pessimistic scenario as it assumes a business-as-usual scenario. It expects a global population of 12 billion and three times the current rate of CO2 emissions by 2100, projecting a global temperature increase of over 6 degrees Celsius.

What do we do to stop global warming?

It would be daunting to keep the temperature rise below 2 degrees Celsius. This would mean global emissions should drop by at least 40 to 70% by 2050 and continue to drop by the end of 2100. After reducing emissions significantly, the next task is removing carbon dioxide from the atmosphere.

87% of our energy comes from fossil fuels, and only 13% is from low-carbon sources like wind, solar, hydroelectric, and some nuclear power plants. This is why we are not reducing emissions.

The IPCC recommends that to stay below 2 degrees, the world needs to increase its use of clean energy by up to 3 to 4 times and continue to scale up. Second, we must become more energy efficient at home, work, and in cars, stop cutting down forests, and reduce emissions from the agriculture and cement manufacturing industries. The longer we put off lowering emissions, the harder it gets and the more severe the outcome will be.

What are we doing about climate change?

There is a serious gap between ambition and action. Big economy nations with the most significant carbon emissions should lead the way in CO2 reductions, while all nations worldwide should do the same. The 2015 Paris agreement soliciting pledges and policies to cut down emissions from all nations is voluntary and, therefore, does not require any accountability or repercussions from any nations if not followed.

With our current policies, the world will hit peak emissions by 2030 or later. And by this time, its effects on the climate will be too late to undo.

Countries worldwide need to be more aggressive on their 2-degree goal. Sadly, Germany is giving up on its near-term targets, and many others are lagging in their climate change commitments.

Rich countries that have already developed and built their wealth by using fossil fuels should help poor and developing countries trying to grow their economies. Still, they are deprived of the ability to use the same fuel.

However, it is not only through the Paris Agreement that climate policies and actions should be based on. Several other actions can be rigorously used to reduce emissions, as seen in the table below:

The science on climate change is clear, and solutions and technology are available to address it.

Big economies and wealthy countries are usually the highest emitters and users of fossil fuels, so their climate actions will have a great global impact and set an example for the rest of the world to follow. The climate crisis is upon us, and we must act now to mitigate and/or adapt to it.