Climate Basics

Warming Stripes for the Globe from 1850-2019, Ed Hawkins  

Upon first glance, this colourful image doesn’t seem to be more than an ordinary pattern; it’s attractive enough you could see it being printed on a pillow, or maybe a scarf.  

Quite to the contrary, it’s actually a striking visualization of climate change, created by renowned climate scientist – and new artist – Ed Hawkins. Traveling left to right, each vertical line represents the annual average global temperature over the last 170 years. The transition from blue to red reveals an alarming truth: our planet is warming, and fast. In this article, we’re going to discuss why, what this means, and most importantly, what you can do about it. 

The Science Behind Climate Change  

Climate vs. Weather 

To understand the dynamics of climate change, it is important to make a distinction between weather and climate. While weather describes short-term changes in the atmosphere (rain clouds, cold fronts, clear skies), climate refers to weather patterns in a particular place, observed over decades. These differences explain why more extreme weather that you wouldn’t normally associate with global warming – like increased snowstorms – could still be attributed to climate change. You can read more about the difference between climate and weather here. 

The Greenhouse Effect 

From natural records found in ice cores, tree rings, and fossilized shells at the bottom of the ocean, scientists know there is a close relationship between greenhouse gases and Earth’s climate, or average temperature and weather patterns.  

Climate change is a consequence of the excess addition -trapping greenhouse gases into the Earth’s atmosphere. Greenhouse gases resulting of heat from human activity, commonly called ‘emissions’, intensify a natural process called the Greenhouse Effect. GHGs trap the sun’s energy within Earth’s atmosphere, instead of allowing it to be reflected back out into space. The higher the concentration of GHGs, the warmer Earth will be.  

How Global Warming Relates to Climate Change 

Global warming contributes to climate change. Global warming refers to long-term increases in Earth’s average temperature since the early 20^th century as a result of industrialization. Since the Industrial Revolution, humans have been burning large quantities of fossil fuels (e.g. coal, petroleum, natural gas). The combustion of fossil fuels is directly tied to global warming because it releases GHGs into our atmosphere. The dual processes of industrialization and globalization have led to dramatic increases in the emission of GHGs as compared to pre-industrial levels, primarily in the form of CO₂.  

CO₂ has caused the majority of Earth’s warming due to it being the most numerous and the longest lasting of all GHGs. Over the last 270 years, atmospheric concentrations of CO₂ have more than doubled – CO₂ levels are the highest they have ever been in the history of humanity, and they are accelerating.  

Data from ice core samples show historical fluctuations in atmospheric CO₂,  

with a rapid spike since the Industrial Revolution 

On the contrary, climate change is long-term changes in global average weather patterns. Although climate change can result from both natural and human causes, among scientists, there is a widespread consensus that the climate change observed today is human-caused and cannot be attributed to a regular shift in Earth’s temperature. 

For years, geologist and academic James Lawrence Powell has been tracking scientists’ views on climate change. In 2019, 100% of 21,000 papers published agreed: climate change is a direct result of human activity.   

Climate Fluctuations 

It is natural for earth’s climate to fluctuate over time. The Earth’s carbon dioxide rises and falls over intervals of approximately 100, 000 years with about 80-90,000 years of ice age and 10-20,000 years of a warm period. Scientists have found strong geological evidence for these changes, like in the trapped gases present in ancient polar ice cores, which have allowed them to construct a detailed record of Earth’s atmospheric composition, something that correlates with climate.  

The difference between past natural climate cycles, and what we are experiencing now, is that increasing temperatures are primarily attributed to the large increase in GHGs as a result of industrial activities. Furthermore, for millennia, natural climate cycling has been very slow, and the level of atmospheric carbon dioxide has never surpassed 300ppm (parts-per-million) – until 1950. 

IPCC original: adapted by John Lang  

In 2019, we reached 415 ppm. This is more carbon than has existed on earth for millions of years; the last time this occurred, pre-humans weren’t even using tools. It becomes all the more incredible, when we realize these changes have occurred in mere hundreds of years. 

What Will Climate Change Look Like? 

Are we already seeing the effects of climate change? The short answer is yes. We can already see the effects of climate change on our environment. A report by the United Nations’ Intergovernmental Panel on Climate Change, one of the most reliable international sources on climate change, estimates that human activity has already caused 1° of global warming since the start of the Industrial Revolution in 1750. 

Already, We Are Seeing the Effects of Climate Change   

• biodiversity loss and varying levels of ecosystem collapse 

• 60% drop in all vertebrate populations in 50 years (1970-2014) 

• melting polar ice has increased by 500% since the 1990s 

• more extreme weather (storms, wildfires, droughts, famines) – map 

• Ocean acidification (coral reefs bleaching)  

• sea level rise of 2.3 inches per year  

Depending on where you are in the world, climate change will manifest itself in different ways. Developing countries, especially those near the equator, are the most severely impacted by climate change, but the least able to adapt to it. You can read more about this issue here. 

Climate change will continue to accelerate unless the heat trapping greenhouse gases that human activity has propelled into the atmosphere and ocean in vast quantities are reduced. The severity of climate change will depend on how successful we are – collectively, as humans – in reducing our emissions to slow the warming effects of greenhouse gases and protecting the biodiversity and ecosystems which sustain all aspects of our lives.