How can humans obtain energy without using carbon dioxide-emitting fuels?
Renewable energy takes the energy of the sun and turns it into
electricity. Examples of renewable energy are hydropower, solar
power, wind, wave and water power, geothermal (using heat from the
centre of the earth) and various forms of biofuels.
Nuclear power is non-renewable, but it does not emit carbon dioxide.
The most realistic options for meeting the massive demand for
energy in the world today and in the future (currently some 15
terrawatts of power) is either nuclear fission or solar
power. All other alternatives simply do not have the capacity
to scale up on the level which is required for global
implementation (for a detailed analysis of this fact, see the Web
Links to the left under "Dr. Nathan Lewis").
While nuclear power could provide sufficient energy to the world carbon free, it would require building a new nuclear power plant every other day for the next 50 years in order to meet demand. Not to mention the problems of national security and the unsolved issues with dangerous nuclear waste that will remain toxic for hundreds of thousands of years.
Solar energy on the other hand has tremendous potential. FACT: MORE ENERGY FROM THE SUN HITS THE SURFACE OF THE EARTH IN ONE HOUR THAN THE ENTIRE WORLD USES ALL YEAR. There are vast supplies of energy in sunlight. The problem with solar energy currently is the cost -- solar cells are simply not economically competitive with other ways of making electricity from fossil fuels (in particular coal). Much more research and development must be done to reduce this cost. The other big problem with solar energy is that currently most solar cells only make electricity, which is difficult to store efficiently. Each night, the sun goes down, and you must have a way to store the energy you will need for the night. Charging and discharging batteries is a very inefficient way to do that. There are solar cells which can produce chemical fuels directly instead of electricity (such as water splitting solar cells that can directly electrolyze water to hydrogen and oxygen). These cells also need a great deal of further research and development before they can be used on a large scale.
See the Related Question links to the left: "What are some alternate sources of energy?"
Most, if not all of the sources of energy listed there are so-called "carbon neutral." Many do not emit any carbon dioxide at all (e.g. solar, geothermal, wind, tides/waves, nuclear), but those that do (biomass) remove as much CO2 from the air as they emit, so that the net is zero.
Humans produce energy through cellular respiration. Humans are heterotrophs and cannot produce their own energy. Humans must consume organic compounds and break them down in order to utilise their chemical energy through cellular respiration. Organic compounds are based around carbon molecules not all organic molecules can be used by humans.
Carbon monoxide (CO) is a poisonous gas, because it replaces the oxygen gas (O2) in your lungs and blood when inhaled. Without oxygen for aerobic cellular respiration, the cells in your body make less energy and eventuallly die, since all organisms (living things) need energy to live. Mammals (including humans) depend on oxygen gas for their vital energy.
carbon dioxide-oxygen cycle is important to us because humans need oxygen to live as well as plants need carbon dioxide in photosynthesis. humans and animals take in oxygen, given off from trees and plants. as humans and animals uses energy, respiration occurs and they give off carbon dioxide which trees and plants need in photosynthesis. without this cycle, or one factor is missing, living things cannot survive because oxygen and carbon dioxide are both useful…
The oxygen that plants make is taken up by humans. The humans take the oxygen and transform it into carbon dioxide. When the humans do this then the plants take it and change it back into oxygen. This is a never-ending cycle, without plants, humans and animals would die out, without humans and animals, plants would die out.
animals,humans and plants are life partners. For example a plant can't live without carbon dioxide so human exhale carbon dioxide in exchange for exhaled oxygen from plants themselves animals,humans and plants are life partners. For example a plant can't live without carbon dioxide so human exhale carbon dioxide in exchange for exhaled oxygen from plants themselves
I guess you could say that humans get their energy indirectly through food nutrients. Food, of all sorts, contain calories, calories are energy. Humans need protein, fat and carbohydrates to live, not to mention water. It is a known fact that a human can live only 5 days without water, but can live up to 30 days without solid food.
Human emitted carbon dioxide, without a doubt. The reason being that humans only emit carbon dioxide, we do not capture and store it again as the natural carbon cycle does. This means that even when us humans only produce 3% of total carbon dioxide emissions (while nature emits the remaining 97%), we can still disturb the balance of the total amount of carbon dioxide in the atmosphere.
Glucose is a product of photosynthesis: Carbon dioxide + Water = Glucose + Oxygen The carbon dioxide travels through the stoma at the bottom of the leaf. The water comes through the roots The light energy, which the chloroplast creates turns the carbon dioxide and the water into glucose, which the plant keeps for energy and then releases the oxygen for humans to breathe in.
No they could not since cellular resporations main purpose is to produce ATP. ATP is basically an energy source and without energy, cells cannot operate. If the cells don't work, humans would nor survive since humans are made up of cells which do various jobs in the body that are extremely vital to being alive.