It’s no secret anymore the average earth temperature is increasing at an unusual rate. But what does it mean exactly? And how can we be so confident it is happening? To answer these questions I will briefly discuss how earth’s climate is measured by scientists, and how we can be confident that human activity is affecting it.

For the sustainability you don’t yet know.

How can we know climate change is even real?

Written by Axel Gizard

This week we have a BONUS article from Axel Gizard, Vice President of External Affairs at the John Molson Supply Chain and Business Technology Association and Academic Delegate for the John Molson Competition Committee! This opinion piece asks the questions we’re all thinking when we see big climate change headlines and provides guidance on some of the more technical terms surrounding the topic. Happy reading!  

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It’s no secret anymore the average earth temperature is increasing at an unusual rate. But what does it mean exactly? And how can we be so confident it is happening? To answer these questions I will briefly discuss how earth’s climate is measured by scientists, and how we can be confident that human activity is affecting it.

How is climate change measured?

Accurate measurement of the planet’s temperature started in the 1880’s and its accuracy continued improving throughout the 20th century. Weather stations around the world collected temperature measurements from ocean and continent. Then, scientists aggregated the data collected to calculate an average, which is why we today have access to the average earth temperature since 1880. The scientific teams that calculated the yearly average temperature excluded anomalies to have more accurate results. Today, this method is supported by satellite data which makes collected data more accurate than ever before. While the confidence interval at the time was around 0.3 °C, it is today below 0.1°C.

How are we sure that the climate is getting warmer?

Between 1880 and 1960, earth’s average temperature was relatively stable and stayed around 14°C. However, since the end of the 70’s, the temperature has been continually increasing by around 0.2°C every decade. In fact, between 1980 and today, the average temperature has increased by a total of 1°C compared to 1880.

There used to be yearly variations of temperature, with one year being colder than the other. Today, when a year is supposed to be colder than the previous one, the temperature is in fact higher than ever. The 10 warmest years across the entirety of recorded human history have all occurred since 2005 and the 5 hottest years were the last 5 years.

How are we sure climate change is caused by men?

Out of all the hypotheses made by scientists, the only factor that can explain the steep increase in temperature is the growing presence of Green House Gas in the atmosphere. Climate scientists have run sophisticated models trying to explain the warming of the earth, and all conclusions led to GHG being the main cause of this steep increase in temperature.

In short, the Green House effect retains heat from the sun and warms the planet to make life on earth as we know it is possible. It exists with, or without human activities. Therefore, the problem is not green house gas, but the rapid and important increase of GHG in the atmosphere caused by our modern lifestyles. To conclude, we are unbalancing a process that made human life possible on earth.  It is therefore imperative to adapt and change the way we live.

References:

https://argonautes.club/quelles-observations-pour-estimer-la-temperature-a-la-surface-de-la-terre.html

https://www.space.com/17816-earth-temperature.html

https://www.currentresults.com/Environment-Facts/changes-in-earth-temperature.php