How and why is the USA so wasteful of the Earth's resources and how is
it affecting the world?

Hmm... sounds like a homework question. Seventh grade social studies, perhaps?

Why the USA is so wasteful is because of the intersection of geography
and economics: for one thing, the US is a big place, so it takes a lot
of energy to move raw materials, manufactured products, etc. to their
destinations.

As for economics, capitalism encourages consumption to the point where
a lot of waste and innefficiency occurs. You could even argue a
certain amount of "waste" is good for the system, helping it to grow
(thus causing even more waste, in a positive feedback loop).

I hope you get an A+ on your report card.

(P.S.: are there any Ph.D.'s out there who can help this poor kid?)

The USA does not waste energy greatly. This is a wrong concept and
arises out of the total oil consumption figure. All energy can be
divided into 5 types - crude oil, Natural Gas, Coal, Hydel and
Nuclear. If you consider all the energy, an average American consumes
about 3,000 Kgs. of Crude Oil equivalent of energy per year, which is
lower than many countries like Kuwait, Saudi Arabia, UAE, etc. The
fact is - USA has a GDP which is 20% of the GDP of all countries on
the earth. There is a direct relationship between GDP and the Energy
Consumption. Since GDP is very high, the energy consumption is bound
to be very high. So, America consumes 25% of energy being consumed by
all the countries. Further, America is huge and has varying climates.
It has desert climates and cold climates both of which require energy.
Yes, America can slightly reduce consumption by increasing the cost of
Gasoline to the level of EU and Britain. If USA has continued the way
it consumed energy in say 1970, its energy consumption would have been
higher by say 50% compared to the present consumption. A great lot of
energy conservation has been put in place already by US Industries and
more is being done every day. Hope you got the total picture.

The USA is the world's richest country and as such is the largest user
of the Earth's resources.
The American society is based on money and if a company can use a
resource a cheaper way, it will. Most cheaper ways to use a resource
involve less pollution control, less restoration, less replacement,
less recycling, more garbage, more waste, etc.
Resources include energy, food production, fishing, mining,
manufacturing, intelligence or knowledge, and many others.
If a natural resource is used, a person should consider what its end
product is; such as oil produces air pollution and is non-renewable.
However solar or wind energy are renewable energies without pollution.
Metals come from minerals and if tossed into the garbage instead of
being recycled, it is wasting Earth's resources.
Overfishing without proper controls has depleted the fishing industry world wide.
It goes on and on. Anything that is used or consumed has another life
afterwards, possibly as garbage, pollution, waste, etc.
Americans have knowledge to be less wasteful of the Earth's resources,
however it is cheaper to waste these resources than to use the
knowledge and be more resourceful to be less wasteful.

See: Small is Beautiful by EF Schumaker:
Small is Beautiful EF Schumaker. This classic text of humanist
economics is celebrated in a 25th anniversary edition, which brings
Schumaker?s ideas into