Chemistry of the atmosphere

• Volcanoes gave out gases
• Some carbon became trapped in fossil fuels and rocks
• Over time, much of the carbon dioxide (CO2) was removed from the atmosphere
• Lots of the carbon dioxide dissolved in the oceans
• The dissolved carbon dioxide formed carbonates that precipitated as small, solid particles sediments
• When green plants and algae evolved, they took in some carbon dioxide during photosynthesis
• Over a long period of time, the oxygen levels built up in the atmosphere
• Before volcanic activity, the Earth didn't even have an atmosphere
• Scientists can get information about what Earth's atmosphere was like in the past from ice cores
• Crude oil and natural gas that are made this way are called fossil fuels
• Green plants and algae produced oxygen about 2.2 billion years ago
• The composition of the atmosphere has been similar for about the last 200 million years
• Nitrogen makes up about 78% of the Earth's atmosphere, and the other gases make up less than 1%
• The current composition of the atmosphere is not too much CO2, and enough O2 - perfect for life on Earth
• Carbon dioxide is a greenhouse gas
• Some radiation heads back towards the Earth, causing the greenhouse effect
• Greenhouse gases trap some of the long wavelength radiation emitted by the Earth
• Some forms of human activity increase the amount of greenhouse gases in the atmosphere
• Deforestation, burning fossil fuels, agriculture, and creating waste all increase greenhouse gas emissions
• Greenhouse gases aren't all bad - we need them to survive
• Without greenhouse gases, the planet would be incredibly cold and unable to support life
• The overall balance of gases in the atmosphere matters
• Higher global temperatures could cause ice in the Arctic and Antarctic to melt, leading to sea level rise
• Changes in rainfall may cause some regions to get too much or too little water
• Extreme weather events may become more frequent and severe
• Changes in temperature and rainfall may affect the production of food in certain places
• Measuring carbon footprints can be tricky
• Reducing greenhouse gas emissions isn't simple
• Alternative technologies that release less carbon dioxide still need a lot of work
• Many governments are worried that making changes to reduce emissions will affect the economy, which could be bad for people's well-being
• This makes it hard for countries to agree to reduce emissions
• Individuals in developed countries also need to make changes to their lifestyles, but some don't want to and others don't understand why the changes are important
• The combustion of fossil fuels releases gases and particles into the air
• Particulates can get stuck in the lungs and cause damage
• Carbon monoxide is produced during incomplete combustion and can be very dangerous
• Sulfur dioxide and oxides of nitrogen can also be released during the combustion of fossil fuels
• Sulfur dioxide and oxides of nitrogen can form acid rain, which damages buildings, statues, and metals
• Sulfur dioxide and oxides of nitrogen also cause respiratory problems if breathed in