date: Tue, 17 Jul 2007 15:26:15 +0100
from: Tim Osborn <t.osbornatXYZxyz.ac.uk>
subject: Re: carbon emissions
there is no absolute "proof" in science, but rather observations
together with explanations for those observations that are called
hypotheses, theories or laws (depending on the degree to which the
explanation has been tested, how well it has passed those tests, and
the degree to which it is generally accepted).
The greenhouse effect provides the link between extra carbon
emissions and global warming, and is often described as a theory,
given that it has been relatively well tested and as a result is
The greenhouse effect theory is complex, in that it depends upon many
different processes each behaving according to various laws, e.g. the
size of the increase in atmospheric CO2 concentration following extra
carbon emissions is determined by various chemical and biological
processes that remove some of the extra CO2, e.g. the effect of the
remaining extra CO2 on the heat balance of the Earth is determined by
various physical laws that quantify the emission and absorption of
radiation by different gas molecules and that determine the flow of
the atmosphere etc.
As a result, it is difficult to point you towards a single piece of
research that is, on its own, able to demonstrate testing of the
greenhouse effect theory, because acceptance is based on a huge
number of studies that have tested individual processes or components
within this complex theory, and even those studies that have
attempted to test the overall sequence of events from carbon
emissions through to global warming/climate change could not be
relied upon individually -- rather it is the combined message from
multiple studies that has led to widespread acceptance of the
greenhouse effect theory.
The Intergovernmental Panel on Climate Change (IPCC) has reviewed and
summarised many of these strands of evidence, so I would suggest that
you read their recently-published summary for policymakers available here:
especially, for example, the diagram on page 11.
This summary is based on a full report, the chapters of which are
Chapters 1 and 9, together with the studies that they refer to, might
be of most interest in terms of the development and subsequent
testing of the greenhouse effect theory.
I hope you find this reply useful.
>From: Margaret and Paul [mailto:firstname.lastname@example.org]
>Sent: Monday, July 16, 2007 10:49 AM
>Subject: carbon emissions
>I am an ordinary person, trying to fathom the whole global warming
>I am trying to establish the proof that carbon emissions are causing
>Can you direct me to any research that proves this point.
>I am looking for proof, rather than an association.
Dr Timothy J Osborn, Academic Fellow
Climatic Research Unit
School of Environmental Sciences
University of East Anglia
Norwich NR4 7TJ, UK
phone: +44 1603 592089
fax: +44 1603 507784