GHG Levels & Emissions

The following pages include articles about climate change topics not addressed on other pages.  They are arranged in 9 major groups: GHG Levels, Emissions, Economics, Investors, Companies, Companies in Politics, Geo-Engineering, Misc. Solutions, and Misc. Science.

     Month and year follow each article's name.  PDF files are so marked, after month and date, some with authors noted.  Within sections, more recent files appear above older files.

    Diagrams are generally immediately below the summary articles from which they were taken.

Scenes from a Melting Planet - A Review of Climate Change Novels 0713 - 18 novels mentioned, some reviewed in a little depth

Greenhouse Gas Levels

in Graphs, over multiple time frames

IPCC 2001

CO2 Levels

    The key greenhouse-gas increases were caused by human activities.

     Compared to natural changes over the past 10,000 years, the spike in concentrations of CO2 & CH4 (methane) in the past 250 years is absolutely extraordinary.
    We know humans are responsible for the CO2 spike, because fossil CO2 lacks carbon-14, and the drop in atmospheric C-14 from the fossil CO2 additions is measurable.

CH4 & Its Concentrations

by European Environment Agency

     CH4 levels increased much faster than CO2 levels from 1800 to 1950.  Why?  Coal? (Canary in the coal mine)

N2O Levels

GHG Emissions

     Historic Emissions that have accumulated in the air are often called Legacy Emissions.

Dr. Fry’s Note

     The set of 4 graphs, from the IPCC to 2100, do a poor job of recognizing the role of legacy emissions (above).  These emissions will keep on raising global temperatures for decades, mostly by feedbacks we have set in motion: less reflection (albedo) from snow, sea ice, sulfates (from burning coal), and clouds (which are more complicated).  The direct (albedo) global warming effect of loss of sulfates, snow, northern sea ie and southern sea ice are estimated as 0.35 to 0.4°C each.  All 4 are multiplied by feedbacks from water vapor and clouds, for a total effect of a further 2 to 2.6°C (to 3.1 to 3.7°C) this century.  Later on, shrinking the area of land ice is added, comparable to losing either northern or southern sea ice.

     The set of graphs also assume that CO2 removals exceed emissions from permafrost, which requires greater removals that one would think at first.  There is also a problem of CO2 outgassing from the oceans as they warm up, currently masked by CO2 ingassing to the oceans from the air as atmospheric CO2 concentrations increase.  This requires even further CO2 removals to long-term geological storage.  Also, increased methane emissions (see below) requires further methane and CO2 removals.

The Fluid in Your AC is 1,000s of Times Worse than CO2 for the Climate 1023

     Note: CO2 capture and storage needs to expand at least 10 times as much after 2050.

     CO2 levels were almost as high 4.0-4.2 Million Years ago: 357-405 ppm.

Today’s CO2 level is the highest since 14.1-14.5 MY ago (430-465 ppm).

Global CO2 Emissions Still Accelerating, even as Human Ones Level Off 0516

     The increase in CO2 levels in the air is accelerating, 4-5% per decade, even as human CO2 emissions from fossil fuels are leveling off.
    This suggests that some combination of fading carbon sinks in the ocean and the land biosphere, with rising emissions from natural sources - permafrost, forest fires, methane hydrates, and peat fires - as well as agriculture and land use changes.


Dr. Gene Fry’s projection of the future, for 6 scenarios.  See discussion of permafrost carbon and several medium to large albedo (reflectivity) changes on the this website’s home page.  As the decades pass by, human GHG emissions slowly decline and become overshadowed by albedo changes and natural emissions ramping up.

This graph fails to recognize very much the effects of the albedo feedbacks we have unleashed.

Thus, its connection to 2°C is unrealistic.

Emissions: Graphs - Historical

      A few articles deal with other (SO2, CH4, CFC, HFC) emissions, some jointly with CO2 emissions.

The average CO2 emission annual growth rate has fallen below 1% since 2013.

Carbon Tracker, with a 1.5 to 2 year reporting lag.  USDoE stopped reporting international emissions at the beginning of the Trump administration, in 2017.

     Some 2019 CO2 emissions were well below peaks.

Ukraine 69% from 1988     
Germany 37% from 1979     
Belgium 28% from 1973
UK 44% from 1971
Russia 34% from 1990
USA 14% from 2005
France 39% from 1979
Poland 30% from 1987
Mexico 12% from 2008

     US DoE’s 2021 emissions data for the USA show slightly lower emissions than Carbon Tracker’s, farther above.  For example, 5.14 GT in 2019 by USDoE, versus 5.28 by Carbon Tracker.

U.S. suburbs are up to 4 times more CO2 intensive per household than central cities - or rural areas.

Section Map: Carbon Emissions