Climate change from a scientific perspective

Waste CO ₂ is mainly derived from human activities are posing challenges in the fight against global climate change.

The main focus in the negotiations at the summit COP26 taking place in Glasgow around carbon dioxide (CO ₂ ), the gas causing the greenhouse effect is released when people burn fossil fuels such as coal, oil and natural gas, in addition to factors such as wildfires and land use.

The Industrial Revolution in the late 1800s began to promote the burning of fossil fuels. It provides vital energy for the industry but also significantly increases emissions of CO ₂ even in that century. The measurement system from mid-1900 showed a steady increase of CO ₂ in the atmosphere, with mostly traces directly from the combustion of fossil fuels.

Chart increase density CO ₂ in the atmosphere each year during the period 1960 - 2020. (Photo: NOAA)

Why CO ₂ causes climate change?

When released into the atmosphere, CO ₂ tends to accumulate in a very long time. Only half is absorbed by plants and oceans, the other half can remain in the atmosphere for hundreds of years, causing the greenhouse effect.

Here's how the greenhouse effect works. Our Sun sends a lot of energy to Earth. The Earth absorbs that energy and emits infrared radiation that travels back into space. CO ₂ accumulation in the atmosphere caused partly trapped radiation, as our planet heats up. The higher the concentration of CO ₂ , the stronger the global temperature increases. The concentration of CO ₂ in the atmosphere today is about 414 ppm, nearly one and a half times higher than 280 ppm in pre-industrial times.

2020, when few people driving more and some industries have to stop working for a short time because of the pandemic, emissions of CO ₂ from fossil fuels fell by about 6%, but that does not prevent the increase in the concentration of CO ₂ in the atmosphere, as emissions from human activities far exceed what nature can absorb.

Even when the world stop all operations of waste CO ₂ , it takes hundreds of years to the density of CO2 in the atmosphere reduce "naturally" on the threshold that the carbon cycle of the planet can return status balance.

The graph reflects and predicts the concentration of CO ₂ in the atmosphere before and after 2021. (Photo: Pieter Tans)

How has the temperature increased on the continents?

It is not surprising that the world recorded an increase in temperature on every continent and ocean. However, the increase is not the same in different places because there are many factors that affect local temperature, such as land use (which affects how much solar energy is absorbed and reflected), or other factors. local heating sources such as urban heat islands and pollution.

For example, the Arctic is warming about three times faster than the global average, in part because as the planet warms, melting ice and snow makes the surface more likely to absorb energy than reflect radiation. solar radiation.

The graph shows the increase and decrease in temperature across continents and oceans. (Photo: NOAA)

How does climate change affect the planet?

The interconnected Earth's climate system is very complex, so even small temperature changes can have big effects, such as melting ice and rising sea levels.

Studies have shown that rising temperatures affect precipitation, glaciers, weather patterns, tropical cyclone activity, and hurricanes. Heat waves are also increasing in frequency, duration and severity, affecting ecosystems, human life, commerce and agriculture.

Most sea level records show a consistent increase over the past 150 years due to melting ice and expanding oceans. Rising sea levels exacerbate coastal flooding.

Climate scientists are working hard to predict the future impact caused by increased emissions CO ₂ and other expected changes, such as the world population. It is clear that temperatures will increase and precipitation will change. How specific depends on many interacting factors.

Forecast of temperature increase in the period 2081 - 2100 compared to the period 1995 - 2014. (Photo: Claudia Tebaldi, et al., 2021).

A few reasons to hope

One positive thing is that scientific studies are constantly improving our understanding of the Earth's climate and complex systems, thereby helping to identify the most vulnerable areas and provide guidance. to reduce the effects of climate change.

Research on renewable and alternative energy, as well as solutions to capture carbon from the air, is creating more options for a better prepared society.

At the same time, as individual awareness increases, many people begin to look for ways to reduce their own impact. The market for electric vehicles, as well as solar and wind power, is growing at an unprecedented rate. More and more people are willing to adopt new strategies for more efficient use of energy and more sustainable consumption.

Scientists believe that converting fossil fuels to renewable energy is the key to combating climate change, with direct benefits to human health and ecosystems.