There is a strong scientific consensus that the planet’s climate is changing and that these changes are predominantly caused by human activities. This consensus is supported by many various scientific studies and by scientific organizations, most of which explicitly agree with the Intergovernmental Panel on Climate Change (IPCC)[i]. Nearly all climate scientists (97–98%) support the consensus on anthropogenic (i.e. human caused) climate change[ii] [iii]and the remaining 3% of contradictory studies either cannot be replicated or contain mistakes[iv].
The suggestion that climate could be affected by carbon dioxide concentration in atmosphere was already mentioned in the 19th century[v]. Later, measurements made in 1958 showed that the CO2 concentration was increasing, now convincingly attributed to human activities such as the burning of fossil fuel [vi] [vii] and later on also to deforestation[viii]. In 1995, the IPCC declared that “The balance of evidence suggests a discernible human influence on global climate” [ix]—a conclusion that has been substantially strengthened by scientific research in the past two decades. A climate emergency has been issued since 2016 by several countries to set priorities to mitigate climate change[x].
These facts raise two important questions. First, how will the climate change in the future? Second, how will the change affect humans and the natural environment? However, before we answer these questions in our next article, let’s start by looking at the differences between climate change, global warming and the weather.
Global warming refers only to the Earth’s rising surface temperature, while climate change includes global warming together with the “side effects” of warming such as melting glaciers, heavy rainstorms, or more frequent droughts. In other words, global warming is one symptom of the much larger problem of human-caused climate change.
Another distinction between global warming and climate change is that when global warming is discussed in media, it is almost always referred to as human-caused warming. This is because the warming is due to the rapid increase in carbon dioxide and other greenhouse gases mostly from people burning fossil fuels; coal, oil, and gas. Climate change, on the other hand, can mean human-caused changes and/or natural ones, such as ice ages. Besides burning fossil fuels, humans cause climate changes by emitting aerosol pollution or by altering the Earth’s landscape – from carbon-storing forests to carbon-producing farmland[xi].
Lastly, Climate change and weather are connected yet they act on a different scale. Weather is what conditions of the atmosphere are over a short period of time, and climate is how the atmosphere “behaves” over relatively long periods of time [xii]. Therefore, if it snows in your country it does not mean that global warming and climate change are not real.
The warming of the global climate is expected to continue in the 21st century. However, the magnitude of the change strongly depends on future anthropogenic greenhouse gas emissions and the sensitivity of climate to them[xiii].
In our next article we will look into the future and the impacts of the climate change.