Unlike meteorological phenomena (weather), climate is the average of weather conditions characteristic of an area. What we call climate change is global change, most evident in the change of temperature of the Earth’s surface and the lower layers of the atmosphere. These are general definitions, concerning all possible climate conditions. Clearly, there were many climate changes over the course of history of our planet, changes resulting from different, but always natural causes. This is an indisputable fact, but one that is not to be taken as an argument for justifying or denying climate change.

Namely, what is not only obvious, but also verified by billions of individual, systematized objective measurements conducted by tens of thousands of scientists, published in peer-reviewed scientific journals and ultimately turned into several thousands of pages of the Intergovernmental Panel for Climate Change (IPCC) report are several key facts on current climate change:

1. The current climate change is neither the first nor the last in the geological history of our planet;
2. Climate change can be caused by several different factors (including orbital changes, volcanoes, etc.), some of which can be anthropogenic;
3. The current climate change is caused by temperature increase, which correlates directly to the rising concentration of greenhouse gases in the last 200 years, i.e. since the beginning of the industrial revolution;
4. The increased concentration of greenhouse gases relates to the consumption of fossil fuels as main source of energy in the industrial age;
5. A whole series of measured parameters clearly and undeniably demonstrates that the excess of CO₂ in the atmosphere comes from fossil fuels;
6. Large volcanic eruptions lead to short-term decreases in average global temperature, insignificant in comparison to the predominant trend of increase;
7. Climate models (sophisticated programs containing best available theoretical models, which underwent a rigorous scientific verification and which enable the calculation of multidimensional problems using the most powerful available supercomputers) reproduce the current trends only after taking anthropogenic factors into consideration.

All of the above tells us that natural processes do not provide a sufficient set of parameters for modeling the current climate change. Consequently (but also using a much deeper analysis) we conclude that anthropogenic factors are the main contributor to the current climate change. These are objective facts based in science.

The consequence of all this is not “slightly warmer weather” – the increase in temperature is the result of a warmer atmosphere, and warmth, as we know, is a macroscopic consequence of kinetic energy of the particles composing the atmosphere. An increase in temperature results in a series of processes that we witness more and more frequently and that are most evident in extreme weather conditions: stronger and more frequent hurricanes, heatwaves in the summer and bouts of extreme cold in winter, droughts and floods, changing distribution of plant and animal species, sea level rise, melting glaciers, etc. Of course, all this has social consequences as well: we are witnessing mass migrations of people (in large parts caused by climate change) with the prospect of hundreds of millions of climate migrants, more frequent conflicts over basic resources (e.g. depleted water resources and scarce agricultural land due to desertification), but also the disappearance of whole traditional cultures due to the degradation of ancient environments.

These are complex processes, and science can give important guidelines for responding to them. It is important to bear in mind that the climate system is one of the most complex systems we know, ruled by a large number of parameters in constant mutual interaction through positive feedbacks povratne sprege. Therefore, it is important to recognize the so-called false solutions, most often coming from the field of geoengineering – the intentional modification of certain aspect of ecosystems in order to artificially reduce incident sunlight, etc. Several experiments have shown that these strategies do not work because they approach a very complex system in an oversimplified manner. What we need is a joint action by scientists from all disciplines, from natural sciences, to engineering and social sciences and humanities, in cooperation with social movements. We need new technologies, but they are not sufficient. They need to be accompanied by a change of the predominant social and economic paradigm based on an unfounded narrative of constant growth. This has to be the basis of the kind of Green New Deal we want.