When we talk about greenhouse gas (GHG) emissions in the corporate world, it's easy to get lost in the numbers and reporting requirements. But, let's take a step back and understand the fundamental science behind why we're measuring these emissions in the first place.
Earth's natural thermostat
The greenhouse effect is essentially the way heat gets trapped close to the Earth's surface by what we call GHGs. Think of these gases as a blanket wrapped around our planet, keeping it warmer than it would be without them. Scientists have determined that CO₂ specifically has a warming effect that helps stabilize Earth's atmosphere.
Here's something that might surprise you: if we completely removed CO₂ from our atmosphere, we would lose the terrestrial greenhouse effect entirely. The Earth's surface would be about 33°C or 59°F cooler. That's why the Earth is sometimes called the “Goldilocks planet”—our conditions are not too hot, not too cold, but just right to allow life to flourish.
Part of what makes the Earth so livable is its natural greenhouse effect, which keeps our planet at a friendly 15°C or 59°F on average.
The human factor
However, in the last century or so, human activity has been interfering with this natural energy balance. This interference comes mainly through the burning of fossil fuels that add CO₂ to our atmosphere. As a result, the level of CO₂ in our atmosphere has been rising consistently for decades, leading to the trapping of extra heat on our surface and causing temperatures to rise. This is what we know as climate change.
Breaking down the numbers
When we look at GHG emissions, CO₂ represents over three-quarters of all emissions, primarily from fossil fuel use and land use changes like deforestation. The second most significant contributor is methane (CH₄), which comes mainly from agriculture, waste management, and energy use. Then, we have nitrous oxide from agricultural activities and fossil fuel combustion and finally, fluorinated gases from industrial processes and refrigeration.
Why this matters for business
According to the Intergovernmental Panel on Climate Change’s (IPCC) Sixth Assessment Report, global surface temperature has already increased by about 1.1°C since the late 19th century. Most of this warming has occurred since the 1970s, largely driven by human activities. Without a strengthening of policies, the IPCC projects that global temperatures could rise by around 3.2°C by 2100. This is no longer just an environmental issue, it’s a business continuity challenge.
The World Health Organization (WHO) reports that an estimated 3.6 billion people live in areas highly vulnerable to the impacts of climate change, including extreme heat, floods, storms, and shifting patterns of infectious diseases. The organization projects that climate change could cause approximately 250,000 additional deaths per year between 2030 and 2050, primarily due to undernutrition, malaria, diarrhea, and heat stress. These escalating health risks underscore that climate change is not only an environmental issue but also an urgent public health emergency with far-reaching implications for global stability, equity, and human well-being.
Remember, we must first know where we are, so we know where to go.
Read another blog about Sustainability from Ryan Lynch: Decarbonization can't wait
Meet our carbon reduction experts
Desmond Zheng, MSSE, Consultant specializing in sustainable engineering, with a focus on renewable energy
Chen Seak Moon, Senior Program Manager specializing in sustainability supply chains
