Combustion of hydrocarbons such as methane (CH4) produces carbon dioxide, a "greenhouse gas." Greenhouse gases in the Earth's atmosphere can trap the
Sun's heat, raising the average temperature of the Earth. For this reason there has been a great deal of international discussion about whether to regulate the
production of carbon dioxide.

Carbondioxide is a greenhouse gas which is responsible for the global warming of the earth and also acidification of ocean water which makes the water unsuitable for marine organisms. This concentration of carbondioxide gas is reduced by planting more trees because plants reduce the amount of carbondioxide gas in the atmosphere by absorbing it in the process of photosynthesis. Less consumption of fossil fuels is also considered a good method to decrease carbondioxide concentration. Replace of conventional cars with the electric cars also reduces pollution in the environment due to carbondioxide.

explanation:

the largest database of organic compounds lists about 10 million substances, which include compounds originating from living organisms and those synthesized by chemists. the number of potential organic compounds has been estimated at 1060—an astronomically high number. the existence of so many organic molecules is a consequence of the ability of carbon atoms to form up to four strong bonds to other carbon atoms, resulting in chains and rings of many different sizes, shapes, and complexities. the simplest organic compounds contain only the elements carbon and hydrogen, and are called hydrocarbons. even though they are composed of only two types of atoms, there is a wide variety of hydrocarbons because they may consist of varying lengths of chains, branched chains, and rings of carbon atoms, or combinations of these structures. in addition, hydrocarbons may differ in the types of carbon-carbon bonds present in their molecules. many hydrocarbons are found in plants, animals, and their fossils; other hydrocarbons have been prepared in the laboratory. we use hydrocarbons every day, mainly as fuels, such as natural gas, acetylene, propane, butane, and the principal components of gasoline, diesel fuel, and heating oil. the familiar plastics polyethylene, polypropylene, and polystyrene are also hydrocarbons. we can distinguish several types of hydrocarbons by differences in the bonding between carbon atoms. this leads to differences in geometries and in the hybridization of the carbon orbitals.

indicate valleys, hills, steepness and gentleness of slopes.

explanation:

contour lines on a map indicate elevation, or depth. numeric notations on contour lines refer to the level of elevation, or height about sea level.