There are many independent pieces of evidence that the climate is changing. Not only the measurements of air temperature but also the amount of energy stored in the ocean, surface of sea ice, mass of ice sheets and others.
What is climate change?
The term climate means the average state of the atmosphere and the ocean on the scales from several years to millions of years. Climate changes result from external factors such as the amount of solar radiation or internal factors such as human activity (anthropogenic changes) or the influence of natural factors.
Climate change is a difficult and controversial topic. Documented data clearly show that the evolution of climate is a completely normal and occurring thing for millions of years. At that time, the Earth has witnessed many periods of differentiated average temperatures. During the ice ages it was much colder and in other periods much warmer than today. Over the past two centuries, however, climate change has progressed much faster than ever before. Since the beginning of the 20th century, the surface temperature of the globe has risen by approximately 0.75 ° C, and by the middle of the current century it may increase by a further 1.5-4 ° C.
What is a cause of a climate change?
Understanding all the consequences of the recent changes requires a thorough understanding of the causes and effects of climate change, as well as mechanisms of extortion or physical phenomena that cause changes in the atmosphere and climate system response to these extortions.
The climate of our planet has been constantly evolving for millions of years. Solar activity, cyclical changes in the orbits of our planet, the thickness of the snow-ice cover, as well as the concentration of aerosols and greenhouse gases in the atmosphere have always influenced the average annual temperature or sea level on Earth.
It should be emphasized that climate scientists have conducted a whole range of analyzes, using a variety of methods to extract the impact of individual natural and anthropogenic phenomena on global warming. All of these studies, using a wide range of independent methods, provide many lines of evidence that global warming over the past decades is caused by humans.
Is climate change real?
Many different studies show that man is responsible for the vast majority of temperature increases observed since the mid-twentieth century. Although our emissions from fossil fuel combustion are only about 5% of emissions from natural sources, they represent a constant surplus that accumulates year after year in the atmosphere. The impact of this surplus on the climate is compounded by positive feedback – mainly due to the effects associated with the operation of water vapor. In the last two centuries, we have been witnessing a drastic acceleration of the pace of climate change. The basic factor shaping the pace of these changes is the emission of carbon dioxide and other greenhouse gases generated during the use of fossil fuels. For climate change to occur, it must be forced by this factor. Today, these are the greenhouse gases we emit. No other extortion matches the specifics of current warming.
Impacts of climate change
The reasons for climate change can be divided into two groups: changes caused by (a) natural factors, (b) anthropogenic effects (human activity). Many scenarios of general climate change are formulated in the form of simple feedback hypotheses, in which changing one parameter changes other parameters. Examples of reasons for climate change are described below. There are many other hypotheses.