From: "Roger Coppock" <[EMAIL PROTECTED]>
Newsgroups: gmane.science.general.global-change
To: "globalchange" <[email protected]>
Sent: Sunday, October 14, 2007 3:23 PM
Subject: [Global Change: 2192] Re: A story problem.
>
> On Oct 14, 10:05 am, "Don Libby" <[EMAIL PROTECTED]> wrote:
>> If by 2050 US energy demand will quadruple, and nuclear generating
>> capacity
>> will double, how much conservation, renewables, and CO2 capture & storage
>> do
>> we need to reduce CO2-equivalent emissions by half?
>>
> Current US energy demand = ???
> (Is this all kinds of energy?
> Does it include say foodstuffs and
> solar energy to grow them? Is it
> just electiric power?)
One good question deserves another, eh? Not including sunshine falling on
leaves of grass, from US Energy Information Administration 2007 Annual,
Table 1.1: Total US energy consumption (all sectors) in 2005 was around 100
Quadrillion BTU, compared with about 45 in 1960.
>
> Current US nuclear generating capacity = ???
>From the same table, 8 quad nuclear, 6 quad renewables.
>
> Current US CO2-equivalent emissions = ???
>
>
>From the House Energy & Environment Committee white paper that you kindly
posted a link to in another thread (source: EPA) total 2005 emissions: 7199
million metric tons CO2 equivalent.
Now, let's change the question in light of the trend in energy consumption
from 1960 to 2005. Instead of a quadrupling, let's hold it to a more
plausible 50% increase, to 150 quadrillion BTU in 2050. Let's suppose that
"business as usual" would lead to a proportional increase in CO2 emissions
to 10,799 mmtCO2eq in 2050. To solve the problem we need to cut emissions
by 50% from 2005 levels to 3600 mmtCO2eq, which is a 67% reduction from BAU
in 2050.
Some other potentially useful facts from the White Paper: in 2005 34% of
total emissions come from electric power generation, 27% of total is from
coal-fired electric, which accounts for 50% of electric power generation,
while nuclear accounts for about 20% of power generation. The transport
sector accounts for 28% of emissions - passenger cars and light trucks about
17%. Residential sector accounts for about 5%, commerce about 6%,
agriculture 8%, and industry about 19% of emissions.
Just thinking about electric power, if total BAU demand increases from 40 to
60 quad BTU, nuclear and renewables double from 14 to 28, and gas and oil
stay the same, then coal would increase from 20 to 26 quad BTU (increasing
emissions from 1944 mmt to 2527 mmt). The remaining sectors account for
5255 mmt in 2005: a doubling of conservation and efficiency in all other
sectors would cut this in half, and a 50% increase in demand would put
future emissions at 3941 mmt, for a total of 6468 mmt, or roughly a 10%
decrease from the 2005 emission level.
Recap: efforts to double energy efficiency, nuclear power and renewable
energy production would cut US emissions about 10% by 2050 (assuming the
historic trend in energy demand continues). The US carbon capture and
storage industry has a mighty big job ahead of them. Even if 100% of
electric power coal emissions could be eliminated by CCS, future US
emissions would be reduced by about 45% (under these assumptions).
Extra credit: "The United States should reduce greenhouse gas emissions 60
to 80 percent by 2050": true, or false ?
(please show your work)
-dl
--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the Google Groups
Global Change ("globalchange") newsgroup. Global Change is a public, moderated
venue for discussion of science, technology, economics and policy dimensions of
global environmental change.
Posts will be admitted to the list if and only if any moderator finds the
submission to be constructive and/or interesting, on topic, and not
gratuitously rude.
To post to this group, send email to [email protected]
To unsubscribe from this group, send email to [EMAIL PROTECTED]
For more options, visit this group at
http://groups.google.com/group/globalchange
-~----------~----~----~----~------~----~------~--~---
