Why we need visualizations for climate change?
Global climate change, with global warming as its main manifestation, is one of the most serious ecological crises faced by mankind since the 20th century. The main manifestations of this crisis are rising surface temperatures and rising sea levels. Since entering the 21st century, many countries and regions have announced that they have monitored the highest temperature in history. This is a very worrying phenomenon.
Organizations and institutions around the world have carried out detailed records of climate conditions in various regions in recent decades or even a hundred years. This allows us to visualize the trend and extent of climate change.
Global surface temperature changes
Overall trend
I used the Earth Surface Temperature Dataset on Kaggle to draw curves of the average temperature and its uncertainty (95% confidence interval) over the past hundred years. In the figure below, the blue curve represents the global average temperature change.
From the above figure, we can see that the global average surface temperature has continued to rise by about 1 degree Celsius in the past 100 years (inaccurate estimation). However, the uncertainty of the global average surface temperature (95% confidence interval) has shown a significant decline and convergence trend. This allows us to conclude that the global surface temperature diversity has decreased and the average temperature has increased. In more and more regions, the surface temperature is rising with a steady momentum.
In the above chart, two colors can distinguish two variables well. The elongated coordinate axis can also reflect the trend change over a long period of time.
Changes in various regions
Although the trend of climate change is global warming, the manifestation of this trend in different regions is also obviously different. Visualization combined with geographic information can well help people recognize the difference in temperature rise in various regions, thereby reflecting the ecological degradation of this region from the side.
Still using the above data set, I made a visualization based on the historical temperature of each major country and city. The figure below is a comparison of the median temperature of major countries and cities in 1913 and 2013. Among them, blue represents low temperature and orange represents high temperature. The bubble size of the city also represents the value of the highest temperature.
As can be seen from the comparison in the above figure, many cities and countries have experienced a significant increase in temperature during the 100 years, and the color has changed from blue to orange.
To reflect this trend, I also added animation to the visualization.
Using colored maps to reflect global warming is a common practice. In the “climate change” entry on Wikipedia, the author quoted the temperature rise map produced by NASA’s visualization studio to show the trend of global warming. This method can give people a very shocking first impression, feeling that the impact of global warming is indeed real and affecting people.
Sea level rise
The sea level rise caused by the melting of glaciers is also an important phenomenon reflecting global warming. The impact of this phenomenon on human society is even stronger than the temperature itself.
I visualized the historical data set of sea level rise, using an area chart to reflect changes and 95% confidence intervals.
We can think of the blue area in the image above as the height of the sea level. It can be seen that in the past 100 years, sea level has continued to increase steadily and exceeded the baseline zero in the 1980s and 1990s. At the same time, similar to temperature, uncertainty shows a downward trend of convergence.
I think that sea level rise brings a stronger sense of crisis than simply considering temperature rise. Island countries such as the Maldives will gradually be swallowed up by the ocean, while the Indonesian capital, which itself is in a low-lying zone with severe ground subsidence, will have to consider moving elsewhere.
Corresponding to the rise in sea level is the melting of glaciers. Katy Daigle and others visualized the changes in the Arctic ice floe provided by the National Snow and Ice Data Center and found that the area of the Arctic ice floe reached the lowest point in history in October 2020. The melting of ice floes causes sea levels to rise, and more ice floes can absorb more heat. Therefore, the year-on-year decrease in the area of floating ice makes people feel very disturbed.
Carbon Footprint
The main cause of climate warming is the emission of greenhouse gases. From my visualization of greenhouse gas emissions, we can clearly see the growth process of carbon emissions in recent decades. Data from Carbon Dioxide Levels in Atmosphere.
In the figure below, I used the dataset to visualize the global carbon footprint and forest footprint in 2016. I used the most intuitive method for color encoding: the darker the green, the less carbon emissions, and the larger the forest area. After all, green is the color of environmental protection.
It can be seen that the carbon emissions of some large countries with better economic development are significantly higher than those of other countries, such as the United States and Australia. Although China’s carbon emissions are not very high, its forest footprint also shows that its ecological and environmental problems cannot be underestimated.
References:
[1] Climate change — Wikipedia
[2] New Compelling Data Visualizations on Climate Change | DataViz Weekly (anychart.com)
[3] Climate Change: Earth Surface Temperature Data | Kaggle
[5] Wild weather, warming planet (reuters.com)
[7] Carbon Dioxide Levels in Atmosphere | Kaggle
