Climate Change and Physics
Climate change affects humans and natural environments today and particularly in the future. Physics play a central role in understanding climate change in-depth and building a climate-friendly world. Important sectors are thermodynamics and electricity. In addition to these, this guide introduces knowledge related to climate change through units and figures.
Climate Change is a Human Expansion of the Greenhouse Effect
The greenhouse effect is defined as the warming of the lowest layer of the Earth’s atmosphere due to carbon dioxide and other greenhouse gases (water vapour and methane, among others). A natural greenhouse effect enables life on our planet, and it occurs when greenhouse gases let the Sun’s heat energy pass through the Earth’s atmosphere and in turn absorbs strong infrared rays i.e. heat radiation. This causes the surface temperature of the atmosphere to remain about 33°C higher than it would otherwise be without a natural greenhouse effect, in which case it would be around -18°C.
Currently, human activity is rapidly warming the globe by adding more greenhouse gases to the atmosphere. Climate change, a human expansion of the greenhouse effect, refers to growing greenhouse gas emissions warming the atmosphere. Carbon dioxide, methane and nitrous oxide in the atmosphere have increased steadily and significantly in the last two centuries after staying relatively steady for thousands of years.
Physical Impacts of Climate Change
When the climate becomes warmer, heat energy gets stored in the Earth’s climate system, mostly in the oceans. For example, it has been estimated that over the period from 1961 to 2003, a total input of heat energy into the Earth’s atmosphere system has increased 15,9 x 1022 joules, from which 90% i.e. 14,2 x 1022 joules has ended up in the oceans.
Although the consequences of global warming are primarily seen in the physical environment, the changes have various widespread impacts on life. Climate change changes ecosystems, wildlife habitat, food production and human activities. The following chapters discuss the physical impacts of climate change. For further information about its impacts on nature and human activities, refer to other chapters.
Humans change the Climate
Currently, human activity is rapidly warming the globe by adding more greenhouse gases to the atmosphere. Our modern lifestyle is based on consumption of fossil fuels and almost all human activities cause emissions such as housing, transport, food, consumer goods and industrial processes including the energy use throughout their lifespan.
Besides greenhouse gases contributing to global warming, human activity produces other types of pollution, such as atmospheric particulate emissions that have a cooling effect on the climate. However, we humans can also make choices that have an impact on the amount of personal greenhouse gas emissions we generate. We can, for example, switch to renewable energy, run our cars with biogas or electricity rather than petrol, go vegetarian or reduce the amount of meat in our diet, and choose organic and local food.
The following chapter discusses energy production in detail. For further information about topics related to food and housing, read the text on home economics. You can find out more about electric vehicles by reading the text on technical work.
Climate Change and the Energy System
Energy technology is an interdisciplinary engineering science, which includes all the devices, machines and systems used in energy production, transfer and usage. Modern industrial society consumes large amounts of fuel, and a large-scale use of primary energy is playing a central role in it.
Nearly all human activities require energy, whether that be to provide heating, transportation, lighting or the manufacture of consumer goods.
Before the Industrial era, wood fuel, water wheels and windmills generated most of our energy needs. Coal burning, the steam engine and the Industrial Revolution helped to open up entirely new opportunities to produce goods quicker and cheaper than ever before and improve the broader economic and material wellbeing of humans.
However, our energy system and a growing trend in the consumption of energy are also major drivers of climate change. Fossil fuels are not only emission-intensive but they have poor conversion efficiency, while a considerable amount of primary energy is required to satisfy the demand for energy.
In physics class, focusing on energy systems represents a pragmatic approach to facilitate teaching basic concepts. What is energy and what are its different forms? What are their uses in our daily life? What are the laws of conservation of energy and how are they linked to energy storage? What is power and how can it be used for comparing different energy sources?