Explain how we can reduce our carbon footprint?

Reduce Carbon Footprint by Life

Only 40% of the average American’s carbon footprint is due to their direct energy use. The other 60% is indirect; it comes from everything we buy and use—goods and services. Pay attention to your consumption and waste habits, and you’ll find lots of opportunities to conserve.
Reduce. Reuse. Recycle.
You’ve heard it before, but it’s still great advice. Manufacturing products produces an average 4-8 pounds of CO2 for every pound of manufactured product.
Stop your junk mail with the help of 41pounds, a nonprofit service that contacts dozens of direct mailers to remove your name from their lists.

Buy locally if possible. Shipping burns fuel. A 5-pound package shipped by air across the country creates 12 pounds of CO2 (3 ½ pounds if shipped by truck).
Eat less meat. If you’re already a vegetarian, you save at least 3,000 pounds of CO2 per year compared to meat eaters. If you’re not a vegetarian, just increase the number of vegetarian meals you eat each week by one or two. Also, poultry is less greenhouse gas intensive than beef.
Don’t waste food. Mom was right. About one-quarter of all the food prepared annually in the U.S., for example, gets tossed, producing methane in landfills as well as carbon emissions from transporting wasted food.

carbonfund.org is a good website to look at :)

in the year 2850, humans successfully colonized mars. the martian modules that were constructed could hold only a small population of people. it is now a century later, and the population on mars has grown to 600 people. of the current mars population, 45 people express the recessive phenotype for phenylketon- uria (pku) syndrome (pp genotype).

explanation: