Carbon dioxide and other greenhouse gases (GHGs) are responsible for global warming, the long-term worldwide average warming experienced since the industrial revolution. GHGs arise from human use of fossil fuels for energy. Major emitters of GHGs include both industrialized countries and, in recent decades, developing countries as well. Higher global temperatures cause the extremes of hot and cold, and wet and dry, weather of recent years. This blog examines global warming and its effects.
See the Tabbed Pages for links to video tutorials, and a linked list of post titles grouped by topic.
This blog is expressly directed to readers who do not have strong training or backgrounds in science, with the intent of helping them grasp the underpinnings of this important issue. I'm going to present an ongoing series of posts that will develop various aspects of the science of global warming, its causes and possible methods for minimizing its advance and overcoming at least partially its detrimental effects.
Each post will begin with a capsule summary. It will then proceed with captioned sections to amplify and justify the statements and conclusions of the summary. I'll present images and tables where helpful to develop a point, since "a picture is worth a thousand words".
the world are filing notice of their proposed contributions for reducing
emissions of greenhouse gases in the next 10-15 years, or more.This is being done ahead of the next (21st)
United Nations “Conference of the Parties” (COP) that convenes starting the end of November
2015.Since the 2009 COP in Copenhagen nations have struggled unsuccessfully to
agree to a successor treaty to the Kyoto Protocol (KP) of 1997, which expired in
2012.Recently the negotiators have
moved toward a proposed agreement based on voluntary, but verifiable,
contributions toward emissions abatement, instead of the top-down imposition of
limits as was done in the KP.In addition,
the agreement, which should be finalized in the 21stCOP, will apply to all nations, without
excluding the developing nations as the KP did. This affords the best chance
for agreeing to worldwide reductions in greenhouse gas (GHG) emissions.
arises largely from burning fossil fuels for energy, producing the greenhouse gas carbon dioxide (CO2)
as a waste product.The fraction
remaining in the atmosphere, about two-thirds, retains excess heat from
sunlight (the greenhouse effect), leading to the examples of harms cited above.
outlook for CO2 emissions
from burning fossil fuels has been analyzed up to 2035 and beyond by the
International Energy Agency (IEA).It
finds that in the absence of worldwide action to abate emissions the world will
not succeed in restricting the increase in global average temperature to 2ºC
(3.6ºF) or less above the levels from before the industrial revolution (see
Details at the end of this post).This
result, and others like it, is an urgent call to action.
The 21stCOP, meeting in Paris starting late November 2015, is considering
a draft agreement which calls on all United Nations (U. N.) members voluntarily
to commit to emission reductions of their own formulation, subject to reporting
and verification.The commitment of the U. S., for example, calls for quantitative
reductions in emissions from the American energy economy (see Details).Examples of commitments from two developing
countries, China and India, however, are only to lower the rate of
increase of their emissions over the next decade or more, rather than to reduce
numerically their GHG emissions (see Details).
IEA has shown that without embarking on a rigorous plan to reduce GHG emissions
the world will not succeed in keeping the overall long-term global average
temperature increase to 2ºC (3.6ºF) or less from the start of the industrial
revolution.Many other analyses by
independent research organizations reach a similar conclusion.These findings represent a critical call to
action by the nations of the world to undertake meaningful emission reductions.
The 21stCOP will consider a draft agreement when it
meets at the end of 2015 to achieve such reductions (see Details).In distinction to the terms of the KP and later
proposals to extend its terms, the current draft treaty does not distinguish
between developed and developing countries, nor does it assign defined
reductions in emissions to every nation.Rather, each nation is to submit voluntary commitments generated internally
for the furtherance of the overall objective, in a verifiable fashion.
Commitments by all
nations that have submitted them are available here.This post considers commitments by the
U. S., China and India (see Details).The U. S. provided sound numerical objectives for actual
reductions in emissions.In contrast, China and India have long been fundamentally committed to
expanding their economies, using primarily fossil fuel-derived energy, without
serious regard for the environmental consequences of their actions (see
Details).China began initiatives in recent years to lower its
energy intensity (i.e., increase the efficiency of energy use by using less
energy per unit of gross domestic product).India has subscribed to similar objectives only
within the past year or so (see Details).
China and India pledge only to reduce the rate of increase
of their emissions, seeking to reach a maximum annual rate by 2030 or
sooner.These commitments may be
disappointing for policymakers seeking more aggressive reductions in emissions,
but in each case they represent a significant change from the earlier policies of
these nations of unrestrained growth based on fossil fuels.These commitments by two major developing
countries constitute a significant departure from the structure of the KP, and
may lead to more aggressive commitments for reduction of emissions in later
It is the intention
at the 21stCOP to finalize the draft agreement and issue
it for ratification by each member nation of the U. N.In the U. S. this will likely trigger a major political
struggle involving the current and next Presidents, and Congress.The U. S. rejected ratifying the KP at least partly
because opponents felt that exclusion of developing countries from its terms
while the U.
would have been subjected to emission limits would have put the U. S. at a
competitive disadvantage in world trade.If the final agreement produced by the 21stCOP incorporates the universal voluntary
commitment framework of the draft agreement, the argument that the U. S. would be at a disadvantage would no longer
be valid.It is hoped that the U. S. will preserve its leadership role in the world’s
global warming policymaking and ratify the final agreement as specified here.
The IEA’s World Energy Outlook (WEO) for 2013 analyzed the contributions to CO2 emissions from the mature industrialized countries of North America, Europe and Asia (Organization for Economic Cooperation and Development; OECD) and the developing countries (non-OECD), historically since 1900, and projecting by models from 2013 to 2035.The results are shown in the graphic below, in the left panel.
future projected total accumulated CO2 in the Earth’s
atmosphere.LEFT: Breakdown of
contributions to the total emitted CO2 from industrialized
(OECD) countries (blue) and developing
(non-OECD) countries (orange) for four historical time periods up to
2012, and projected emissions, assuming no actions are taken to limit them, for
2013-2035.Gt, gigatonnes (billion
tonnes).RIGHT: A circle representing
the maximum permissible worldwide emissions of CO2 that keeps the
global average temperature increase from the industrial revolution below 2ºC
(3.6ºF).Historical accumulation 1750-2011 (orange), amount
projected for 2012-2035 (gold), and projected
emission portion remaining (gray) in the limited CO2 budget
Adapted from International Energy Agency, World Energy Outlook 2013
the graphic, left panel, the first three bars are for 30 years, the fourth bar
is for 23 years and the fifth bar, for projected emissions, is for 22
years.Historical and projected
emissions, assuming no actions are taken to limit them, increase dramatically
as time passes.Emissions from the
industrialized world (OECD) level off after 1959, however, whereas those from
developing countries (non-OECD), including major contributions from China and India, have surged and are projected to continue
rising dramatically to 2035.
scientists have calculated the maximum total accumulation of CO2 in
the atmosphere that would limit the increase in the global average temperature
to 2ºC (3.6ºF) or less since the industrial revolution began.This amount is represented as the circle in
the right panel of the graphic above.The sectors show that if no constraints are put on the world’s emissions
most of the emissions budgeted to preserve the temperature limit will have been
committed by 2035 (combining the orange and gold sectors).That leaves a presumably unattainably narrow sector (gray) of emissions in the years after 2035 to stay
below the established temperature limit.The graphic concludes “emissions [are] off track [i.e.,
historical and projected emissions are too high] in the run-up to the 2015
climate summit in [Paris,] France”, taking place at the end of the year, to
limit the temperature rise.
It is critical
that the nations of the world reach agreement on limiting emissions at the Paris conference.The
annual COP conferences, involving all member states of
the United Nations (U. N.), have so far failed to reach agreement on limiting
emissions (and other related issues).This is at least partly because the Convention governing the U. N.
meetings enshrines the opposing points of viewthat nations of the
world address climate change “on the basis of equity and in accordance with
their common but differentiated responsibilities and respective capabilities”.This phrasing reflects the concerns that “the
developed countr[ies] should take the lead in combating climate change” and that
the “specific needs and special circumstances of developing countr[ies]…should
be given full consideration”.
The Kyoto Protocol incorporated this distinction: it applied only to industrialized countries, while excusing developing countries from being held to any emissions limits.Developing
countries point to the large historical contributions to emissions from
industrialized countries (see the graphic, left panel), and feel they should be
allowed to industrialize in the same way.In contrast, industrialized countries recognize that industrialization
in the developing countries will add significant new CO2
contributions to the atmosphere (see the graphic, left panel, projection to
2035), to the world’s detriment.
COP21 will consider finalizing a new draft treatyfor approval.The most important new
departure is that, in contrast to KP, which imposed numerical emissions limits
for each covered nation in the treaty, the new agreement invites voluntary yet
verifiable commitments from every nation for its reduction in greenhouse gas
Examples of Voluntary Commitments.The U.S. is a major contributor to the emissions
from industrialized countries.China, a developing country, is currently the
nation with the highest GHG emissions in the world; it is responsible for a
major portion of the historical 1990-2012 and projected 2013-2035 emissions
shown in the graphic.India, also a developing country, is increasing
its fossil fuel-driven energy production at similar (high) annual rates as China, although its absolute numerical production
is much lower.The voluntary commitments
of these three nations are summarized here.
U. S.The U. S. is committing to reduce its emissions from
the level of 2005 by 26-28% by 2025, with best efforts made to achieve 28%
.President Obama has already put in
place several policies that will contribute to meeting this goal.This program places the U. S. on a longer-term path to achieve an economy-wide
reduction in GHG emissions of 80% by 2050.
China had been a strong proponent of the
arguments presented by developing countries summarized above.Its reconsidered goals were outlined in the summit meeting between Presidents Xi Jinping and Obama in 2014.China’s emission rates continue growing because
it is adding new fossil fuel-driven electric generating plants to power its
expanding economy.Its goal,
confirmed for the U. N.’s 21stCOP, is that the annual rate of GHG emissions
will reach a maximum by 2030 and possibly sooner, and then decline.China’s commitment to slow the growth of its
emissions was not specified in numerical terms.As part of this initiative China expects to use fossil fuel-derived energy
more efficiently, including increasing the share of energy derived from
renewable sources to 20% by 2030, and to expand its forested lands.It is to be emphasized that China’s numerical rate of emissions will not begin
declining until about 2030.
India has been rapidly expanding its energy
production from fossil fuels, especially coal.As recently as 2014, Prakash Javadekar, India’s minister of environment, forests and
climate change, rejected constraining its growth and reducing its emission rate
.India’s first responsibility, he stated, is to
reduce poverty and expand the country’s economy, rather than reduce GHG
emissions.In this regard India’s approach resembles the earlier Chinese
goals.In a change from this policy, India’s commitment for the 21stCOP intends to increase its energy efficiency by
33 to 35% from its 2005 level by 2030.This program includes a goal of expanding non-fossil fuel-derived energy
(currently at a very low level) by 40% by 2030, relying on foreign assistance.In addition it will add new forest lands to
help remove CO2 from the air.It is noteworthy that India, like China, does not state a numerical amount of
actual reduction in its rate of emissions, only a slowdown in the rate of
increase of its emissions.