A changing climate

Glaciers react to changes in climate, so studies of glaciers provide valuable information for climate research.

In Greenland and Antarctica, researchers are extracting several kilometers of ice cores. These cores contain information about the climate in the past, just over 800,000 years ago, and the researchers can tell us that our climate is changing.

The atmosphere - the protective filter around our Earth.

Why are we sure that our greenhouse gas emissions affect the climate?

Figure 1 (below) shows how the concentration of the greenhouse gas carbon dioxide in the atmosphere (red) and temperature (blue) have varied over the last 800,000 years. The natural climate changes during this period have a periodicity of about 100,000 years, with relatively short, warm interglacials and long ice ages. These variations are linked to changes in the Earth's orbit around the sun, which are amplified by greenhouse gas variations.

Through the emission of greenhouse gases, and particularly through the burning of coal and petroleum products, we humans have now raised carbon dioxide levels as much as the natural differences between the Ice Age and the interglacial period. An increase in greenhouse gases must lead to warming, and a warmer atmosphere will also, on average, contain more water vapor and result in increased precipitation.

Figure 1: The figure shows how CO2 concentration in the atmosphere and temperature have fluctuated over the last 800,000 years. The results are found after examining ice cores retrieved from 3,060-3,270 meters down in the Antarctic ice sheet. The figure is modified from Lüthi et al. 2008.

What's happening to the climate?

Figure 2 shows that the global average temperature has risen particularly sharply since 1980. The years 1998, 2005, 2010 and 2014 up to and including 2020 were the warmest years. The 25 warmest years on the Earth's surface since meteorological measurements began have occurred in the last 26 years. Since 1980, every quarter of a decade has become warmer, with the last decade (2010-2019) being the warmest.

Researchers agree that greenhouse gases have increased, and that this in itself leads to climate change. However, it is worth noting that in the period 1940-1980 there was no increase in temperature, despite the fact that the amount of greenhouse gases also increased then. This shows that the climate at any given time is a result of both human influence and natural fluctuations. Researchers still disagree on the forecasts for the climate in the future. This is primarily linked to uncertainty in the balance between natural and man-made changes. In addition, it is still uncertain to what extent the ocean plays a role and how amplifying mechanisms contribute. One particularly important mechanism is when the earth's surface is changed from snow/ice to water.

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Figure 2: Global average temperature 1850 - today. Climatic Research Unit.

Most climate researchers believe that before 2050, the Earth's climate will fall outside the temperature ranges that humans and human-like creatures have experienced. We will then enter a climate world that we know little about, where adaptation may be much more difficult than it will be in the climate that awaits us in the next few decades. Acting correctly in such a world must be based on insight and not fear. 

Sources of anthropogenic CO2 emissions: Coal 39%, oil 33%, gas 21%, cement 4% and other 3%(Global Carbon Project)

If all the people on Earth were to live the way we do, it would require energy and resources equivalent to more than 3 planets...

The climate challenges we face will require action at many levels. The biggest ones must be solved through international and national leadership, but what each individual does is also very important - a little action by many can have a big effect. Here are some tips on what we can all contribute. Close up!

At home:

• turn off lights in rooms you are not staying in

• completely turn off TV, PC, stereo etc.

• turn down the temperature

• install time switches

• use energy-saving bulbs

• sort waste and recycle

In the office:

• use miscopied paper as a drafting sheet

• print two-sided sheets

• send email instead of fax

• turn off your PC & copier at the end of the day

• introduce conference calls and video conferencing

• sort waste and recycle

Transportation:

• use a bike or your legs on short trips

• drive a smaller car, or drive with others

• slow down / maintain the speed limit

• avoid flying - take the train or bus

• invest in an electric or hydrogen car

You can find more tips from Framtiden i våre hender, among others.