Greenhouse Gases

UN report recommends package of 16 measures to rapidly reduce global warming, including clean cook-stoves for developing countries, banning open burning of agricultural waste, stopping methane leaks from mines and pipelines, clean diesels and phasing out wood-burning stoves in wealthy countries.

Non-CO2 substances cause 50% of warming

About half of current man-made warming is caused by substances other than CO2, including methane (CH4), ozone (O3) and black carbon (BC).

Reducing this 50% of warming is vitally important - the graph (produced by a team of 50 scientists from the UN Environment Program and the World Meteorological Organization (UNEP/WMO)) shows  that we are unlikely to meet the Copenhagen limit of 2 degrees without tackling these pollutants.

The UNEP recommended “a range of compelling, and in many cases highly cost-effective options for fast action on BC, CH4 and tropospheric ozone.”[2

Defusing the ‘Ticking Time Bomb’

Reducing emissions of BC, CH4 and ozone precusors produces a rapid reduction in warming (dark blue line on the graph), because these pollutants cause substantial warming, but stay in the atmosphere for shorter periods of time than CO2. A reduction in BC and CH4 emissions therefore produces a big reduction in current warming which prevents future warming by slowing the melting of glaciers and polar icecaps, allowing them to continue to reflect radiation back into space.  

Reducing current warming also helps keep methane locked away in permafrost and frozen undersea stores.  Charles Miller, principal investigator of NASA’s Carbon in Arctic Reservoirs Vulnerability Experiment (CARVE) warned in 2013: "Permafrost soils are warming even faster than Arctic air temperatures - as much as 2.7 to 4.5 degrees Fahrenheit (1.5 to 2.5 degrees Celsius) in just the past 30 years".

NASA’s website explains: “methane is 22 times more potent as a greenhouse gas than carbon dioxide on a 100-year timescale, and 105 times more potent on a 20-year timescale. If just one percent of the permafrost carbon released over a short time period is methane, it will have the same greenhouse impact as the 99 percent that is released as carbon.”  

Prof Carlos Duarte, Director of the University of WA’s Oceans Institute also warned about the devastating consequences if current warming causes substantial quantities of methane to be released from the Arctic: “The amount of greenhouse gas stored in methane hydrates in the Arctic is several times the total CO release since the industrial revolution” see Methane hydrates: a volatile time bomb in the Arctic and all hell breaks loose as the tundra thaws.  

Nobel prizewinner, renowned climate scientist and sustainability expert call for immediate action to reduce greenhouse super-pollutants to stave off climate calamity

   Nobel prize-winning scientist Mario Molina joins discoverer of the greenhouse effect of halocarbons, V. Ramanathan, and the president of the Institute for Governance & Sustainable Development, Durwood Zaelkein calling for immediate action to cut four super-pollutants, which could make the difference between a reasonably safe climate and one that carries staggering human and financial costs.
   "All countries must keep their commitments to pursue aggressive cuts to carbon dioxide under the Paris Agreement. Yet even under full implementation, global temperatures will increase between about 4.5 and 7.2 degrees Fahrenheit, far above the 3.6-degree guard rail. The best and fastest way to prevent immediate climate destabilization lies in cutting back on emissions of super pollutants that make outsize contributions to warming despite the fact that they are produced in much smaller quantities than carbon dioxide. They include ground-level ozone and black carbon soot, from sources such as power plants and diesel engines, as well as methane (often from natural gas systems and agriculture) and hydrofluorocarbon refrigerants (HFCs) in air conditioning and other systems.
  "Cutting carbon dioxide emissions remains imperative, and cannot be delayed. Yet the parallel strategy of reducing super pollutants is perhaps even more important to avert disastrous consequences in the near-term."
"Unless we rapidly slow down these self-amplifying feedback mechanisms, we could lose the first major battle of climate change and face worse problems in the future."
    The report calls for immediate action to reduce these emissions to help limit global temperature rises over the next 20 years that could lead to catastrophic climate change from melting of glaciers and polar icecaps (that reflect radiation back into space) as well as methane permafrost and frozen sub-sea methane, which have been described as a "ticking time bombs" for our climate. 
     Because of current man-made warming (half of which is due to methane, ground-level ozone and black carbonthe Arctic is melting and emitting methane, which is 'certain to trigger further warming'Prof Carlos Duarte, director of the Oceans Institute at the University of Western Australia, warned that the Arctic summer sea ice was melting at a rate faster than predicted by conventional climate models, and could be ice free as early as 2015.  Prof Duarte's article in 'The Conversation' explains why methane hydrates are a volatile time bomb in the Arctic  "The major risk is that the relatively modest human perturbation will unleash much greater forces."  The amount of greenhouse gas stored in the methane hydrates is several times the total CO₂ release since the industrial revolution.  NASA is investigating if a Sleeping Climate Giant is Stirring in the Arctic? the Similar sentimes are echoed by Climate Spectator:We’ve known for a while that ‘permafrost’ was a misnomer (see Thawing permafrost feedback will turn Arctic from carbon sink to source in the 2020s). The defrosting permamelt will likely add up to 1.5 degrees Fahrenheit to total global warming by 2100."

    The immediate increase in global warming from the methane, carbon monoxide and black carbon emissions of wood heaters contribute disproportionately to current warming - in the first 20 years as much as heating 20 similar houses with gas or an electric heat pump, adding to the relatively modest perturbations that could unleash much greater forces if a tipping point is reached. 

July 2017. Thawing Permafrost Poses Even Greater Climate Threat Than Previously ThoughtThawing tundra may be allowing long-buried pockets of methane to be released into the atmosphere, new research suggests. A study surveying the Mackenzie Delta in Canada, published Wednesday in the journal Scientific Reports, suggested that these methane "seeps" on the tundra may be more problematic than previously thought.
   The study finds that 17 percent of methane emissions in the area came from these seeps, despite emissions hotspots only covering one percent of the tundra's surface area. The authors wrote that warming will "increase emissions of geologic methane that is currently still trapped under thick, continuous permafrost, as new emission pathways open due to thawing permafrost."  "We were a bit surprised … we saw these very strong emissions.

CO2 doubled but methane has increased increased almost 4-fold since pre-industrial times
see graph from: 
Mass extinctions and climate change: why the speed of rising greenhouse gases matters

 The graph from the UNEP report (November 2011) shows the effect of the measures to reduce methane (CH4) and black carbon (BC) on global temperatures.  Compared  the purple Reference line (business as usual) the dark blue line shows a rapid reduction in global temperatures of about 0.4 degrees by 2040, complementing the measures to reduce CO2 emissions.  Measures to reduce CO2 result in benefits from about 2040.  By about 2070, half the reduction is due to the reductions in methane and black carbon emissions and about half due to the reduction in CO2 emissions.       

   Over 100 years, methane causes 34 times as much warming as the same amount of CO2, but 88 times as much over the first 20 years. Fast action could help prevent frozen methane from melting and adding to the temperature increases, so that even more methane melts, leading to even greater temperature increases and so on.  This scenario of runaway climate change has been described as a point of no return, or tipping point, which cannot be reversed.   Reduce methane, black carbon and ozone will reduce losses of mountain glaciers and reduce projected warming in the Arctic over the coming decades by as much as two thirds, helping to avoid a tipping point if methane undersea and in permafrost starts to melt.
   Cutting out these pollutants now could also boost global food output and save millions of human lives lost to heart and lung disease, according to the report from the UN Environment Program (UNEP) and the World Meteorological Organization (WMO). Parallel action now on black carbon particles and ground-level ozone would buy precious time in limiting projected global temperature increases of 3.6 degrees Fahrenheit in the coming decades, the report said.

   A peer-reviewed paper in Atmospheric Pollution Research shows that, based on the latest estimates of Global Warming Potentials, over a 20 year horizon the average Australian wood heater causes more warming than heating 12 similar homes with gas (see Table 1).

  Ross Garnaut recommends credits for growing trees, taxes for chopping them down

On April 14, 2011: Professor Ross Garnaut, distinguished Australian economist and author of a review on Climate Change and Policy Response to Climate Change for the Federal, State and Territory governments of Australia, gave a lecture on Climate Change in Armidale, NSW.  When asked about how to account for biomass climate change policy, he argued that people who grow trees, should get credits for the carbon sequestered every year. But people who chop them down (and burn them) should pay tax on the carbon released into the atmosphere.

   This sensible accounting system (which relates directly to the impact on the atmosphere - sequester carbon and get credit; pay the tax when it is burned)  Methane should still be counted, as it is now, but the release of the CO2 dominates.   Under this accounting system,  a comprehensive peer-reviewed paper, published in Atmospheric Pollution Research shows that the average Australian wood heater causes more global warming than heating up to 5 similar homes with gas or a reverse cycle airconditioner. 

    The Kyoto protol used a different accounting system, in which, rather than being counted directly, CO2 emissions from wood burning were accounted for by the change in biomass in the forests and other stored carbon.  This works well for an entire country.  However, if used by individuals, it leads to wasteful and inefficient use of a valuable resource

Example: If the owner of a forest gets a credit for the amount of carbon sequestered every year, but pays a tax when the wood it burned, it may become economic to use thinnings to make wood pellets for power stations, instead of burning coal.  Without this incentive, forest owners are likely to simply burn waste wood on site, leading to much higher total greenhouse gas emissions than by using the wood as a replacement for burning coal. The same applies to domestic wood heaters.  The average Australian wood heater burns 2.7 tonnes of wood, emitting about 6.7 tonnes of CO2-equivalent, compared to 1.3 tonnes of CO2 for centrally heating an entire house with floor area of 160 square metres. 

     Australia’s annual contribution to global warming would be reduced by at least 8.7 million tonnes of CO2-equivalent (the same as removing about 21% of Australian passenger cars from the roads, or generating electricity from 5.8 million household 1 kW rooftop photovoltaic systems) if the 4.5 to 5 million tonnes of firewood currently burned in domestic wood heaters were instead used to replace coal in power stations and domestic wood heaters replaced by gas or reverse cycle air-conditioning.

Global warming from methane
(CH4) emissions from domestic wood heaters
       Even if CO2 emissions from are not counted, incomplete burning in enclosed heaters creates methane (CH4), carbon monoxide (CO, about 15% of carbon emissions) and black carbon smoke.  According to the IPPC Fourth Assessment report (AR4), one kilogram of CH4 causes as much global warming as 25 kg CO2. CO (not covered by the Kyoto protocol) causes 1.9 times as much. 

    A Swedish study of enclosed wood burners used to heat water found that methane emissions can cause up to twice as much global warming as generating the same heat from an oil-fired burner. 

Lab tests: new Australian heaters on low burn as bad as the Swedish model causing twice as much global warming as an oil heater
        On low burn tests under a new test protocol in which the air control was turned down 2 minutes after adding more wood, two of the 4 new Australian models tested had similar emissions to the worst model in the Swedish study. This implies that, even if the wood is from a sustainabe source, under real-life operation,  the methane emissions from a new Australian wood heater used mainly on low burn will often cause much more global warming than heating the same house with gas. 

Lab results confirmed by real-life measurements 
        In Launceston, emissions from AS4013 heaters in the households of volunteers, who appeared to take condsiderable time and trouble to operate their heaters correctely, averaged 9.4 g/kg.  This is the is the best we can expect.  Most people will take a lot less time and trouble, implying that we can expect emissions of 10 to 15 g/kg.  Based on the graph (right) showing the relationship between methane and particle emissions, average amounts of wood burned, and average fuel used by households with non-polluting heating, we can conclude that, even if the wood is from a sustainable source, the average Australian woodheater will cause more global warming than gas or reverse cycle electic heating.

Even worse for global warming if climate reaches a tipping point in less than 100 years   Methane causes substantial, intense warming for some years after emission.  Over 20 years, it causes 72 as much global warming as the same amount of CO2, over 100 years this reduces to 25 times as much.  The Institute for Governance & Sustainable Development explains: With abrupt climate change approaching faster than predicted according to scientists, fast-action mitigation strategies (reducing black carbon, methane, and tropospheric ozone) are essential in order to avoid passing the tipping points.  See also a research paper with detailed info on Australian woodheating and global warming. 

Article in the Prince George Citizen providing a scientific explanation why burning wood produces a lot more CO2 than natural gas per unit of useful energy.  "The basic premise that wood based fuels operate under is that any carbon dioxide produced will be recycled into trees. But there is a word missing from that sentence and it is “eventually”. It takes some 80 years or so for the carbon dioxide released today to be fully capturedAnd with twice as much carbon dioxide being produced for the same amount of energy, that is a lot of additional greenhouse gases being introduced into the atmosphere in the short run."

Pellet heaters cause much less global warming
This problem can be avoided by switching to pellet heaters which emit 95% less health-hazardous PM2.5 pollution and methane per year than the average AS4013 heater.  Average emissions from pellet heaters are  less than1 g/kg, compared to 10 g/kg for the average wood heater, but because the heat is controllable, two or 3 houses can be heated for the same amount of wood burned in a single log heater.  

 Climate change, if left unaddressed, is expected to increase air pollution-related deaths by nearly 60,000 in 2030 and 260,000 in 2100 globally, a study has claimed.

According to the study, hotter temperatures speed up the chemical reactions that create air pollutants like ozone and fine particulate matters, which impact public health.
The most effective ways individuals can reduce their contribution to global warming

New Scientist: Logging study reveals huge hidden emissions of the forestry industry  A life-cycle analysis by economist John Talberth at the Center for Sustainable Economy, an environmental think-tank based in Oregon, US, takes account of factors such as the carbon released as the roots of cut trees rot in the ground and the fertilisers, herbicides and pesticides applied to tree plantations. The conclusion: logging in North Carolina emits 44 million tonnes of carbon dioxide a year.  That makes it the third largest source in the state, just behind electricity generation and transportation, and far ahead of farming and other industries.

Wall Street Journal: Wood Pellets Draw Fire as Alternative to Coal  “The irony is, burning gas would release far less carbon-dioxide than burning wood,” said Bill Moomaw, co-author of five reports for the United Nations Intergovernmental Panel on Climate Change, one of which helped earn the IPCC a Nobel Peace Prize in 2007. Is burning wood for heat green? In a word, no  ... It is probably time to conclude that burning wood isn't green, and it isn't safe. 
Forbes: Wood - The Lethal Renewable Energy Swindle.  Written in April 2017: "Owing to poverty, around three billion people globally cook and heat their homes with wood, twigs and dung. More than four million die prematurely each year because of the resulting indoor air pollution  ... It is estimated that in Europe, small-scale domestic wood and biomass combustion will become the dominant source of the most dangerous particulate air pollution by 2020 ... it will be a bigger source of killer pollution than cars or industry and much bigger than power generation ... Around 3,900 deaths every 24 hours can be attributed to fossil fuels, whereas 11,000 deaths daily are caused by our reliance on biomass."

Increased burning has reduced CO2 uptake of EU forests  
"increased harvesting is reducing the amount of CO2 that EU forests are taking up from the atmosphere – at a time when this needs to be increasing. By 2014,4 EU forests were already sequestering 24 million tons less CO2 than they were in 2009. By 2020, this is projected to drop by a further 57 million tons. Together that’s equivalent to an extra 80 million cars on the road or the annual CO2 emissions of Romania!"
Research in June 2017 by Fern, Birdlife International & Transport International. "Few could have guessed that a policy intended to help the EU meet climate goals would lead to vast increases in the burning of wood, degrading forests in Europe and beyond.

Pulp Fiction: The European Accounting Error That's Warming the Planet - a groundbreaking series by Climate Central on the climate-threatening rise of wood energy, named as a finalist for one national journalism award, and as a runner-up in anotherMost wood energy schemes are a 'disaster' for climate change"The fact that forests have grown over the previous 20 or 100 years means they are storing large amounts of carbon, you can't pretend it doesn't make an impact on the atmosphere if you cut them down and burn them...."You could fix them in wood products or in furniture or you could burn them, but the impact on the climate is very different."

New Scientist: The EU’s renewable energy policy is making global warming worse
May 2019: Dangerous delusions: biomass is not a renewable energy source It may be difficult for many people to accept that burning biomass is just as bad, if not worse, than burning fossil fuels, but this fact is finally sparking national and international movements against the biomass and biofuel industries. 
According to the IPCC Special Report on global warming of 1.5 degrees, we have only 11 years in which to change how we consume and live. The bioenergy and unsustainable biofuel industries operate using the same extractive ideology that got us here in the first place -- an ideology which puts resource exploitation and short-term gains ahead of indigenous rights, local communities and ecosystems.
Jan 2018: MIT Study warns wood bioenergy supporters can’t see carbon emissions for the trees 
A new report from MIT Sloan professor John Sterman supports the growing argument that burning wood pellets for power is worse for the climate than burning coal, because of the short-term effects and the “potentially irreversible impacts that may arise before the long-run benefits are realized.”  ... “It’s like an investment in which you give your bank $1,000 today,” Sterman said in a statement. “They promise to pay you back, but only over 80 years, and only if they don’t go out of business first or decide there’s something else they’d rather spend your money on. You’re better off if you keep your money. In the same way, it’s better to keep the trees on the land and keep all that carbon out of the atmosphere.”  The report pointed to solar and wind power (zero-carbon energy sources) as the safest, easiest, and cheapest ways to cut greenhouse gas emissions.

Different Fuel, same Fire. Almuth Ernsting, Aug 2018. "Wood-based bioenergy is far from carbon neutral and its production has grave consequences for land use and ecosystems around the world  .... 800 scientists recently warned the European Parliament: “Even if forests are allowed to regrow, using wood deliberately harvested for burning will increase carbon in the atmosphere and warming for decades to centuries – as many studies have shown – even when wood replaces coal, oil or natural gas".

Stanford study shows effects of biomass burning on climate, health
   A new study by Stanford Civil and Environmental Engineering Professor Mark Z. Jacobson, has quantified the amount of global warming caused by biomass burning.

  Jacobson said the sum of warming due to all anthropogenic greenhouse gases – CO2, methane, nitrous oxide, chlorofluorocarbons, and some others – plus the warming due to black and brown carbon will yield a planetary warming effect of 2 degrees Celsius over the 20-year period simulated by the computer. But light-colored particles – white and gray particles primarily – reflect sunlight and enhance cloudiness, causing more light to reflect.
    "The cooling effect of these light-colored particles amounts to slightly more than 1 degree Celsius," said Jacobson, "so you end up with a total net warming gain of 0.9 degree Celsius or so. Of that net gain, we've calculated that biomass burning accounts for about 0.4 degree Celsius."
The Arctic is warming at twice the rate of the rest of the world.  In 2016, there were record-breaking high temperatures and low levels of sea ice.  Analysis of samples showed that the Black Carbon in the Arctic was coming primarily from transportation and home heating with coal or biomass.

Sierra Club: Burning wood contributes to climate disruption - EPA-certified stoves are not the answer to woodsmoke pollution  

Sustainable Energy Associations demonstrate the benefits of efficient heat pumps to reduce global warming as well as air pollution.
The workshop, organized by the Sustainable Energy Association of British Columbia, Canada, starts off with a presentation and short videos, and a panel of experts will be there to answer your questions.

Green Building "Claimed carbon savings for biomass energy take no account of the alternative uses of the material. Wood products store carbon for generations and are capable of being reused many times before the carbon they contain escapes back into the atmosphere. Wood should only be burnt for energy production when it has no other viable environmental or commercial use and that is not true of most woody biomass fuel in today’s energy market."
Climate change: Soot's role 'underestimated' says study  "Scientists say that particles from diesel engines and wood burning could be having twice as much warming effect as assessed in past estimates.  They say it ranks second only to carbon dioxide as the most important climate warming agent .... This new study concludes the dark particles are having a warming effect approximately two thirds that of carbon dioxide, and greater than methane."    "Reducing emissions from diesel engines and domestic wood and coal fires is a no-brainer as there are tandem health and climate benefits," said Professor Piers Forster from the University of Leeds.  "If we did everything we could to reduce these emissions we could buy ourselves up to half a degree less warming, or a couple of decades of respite," he added.  Prof Piers Forster is Coordinating lead author of the IPCC report chapter Changes in Atmospheric Constituents and in Radiative Forcing (which sets out the scientific evidence on the changes in the atmosphere that are causing global warming).

Where HAVE all our woods gone? Up in smoke..felling British hard wood forests in order to burn them is harming biodiversity, destroying habitats, and may well increase emissions. ‘Big, hardwood trees are enormous carbon sinks, and take hundreds of years to be replaced.’
U.S. Groups Join Global Call to Remove Wood-based Biomass From European Union Renewable Energy Directive "The declaration submitted today demands that bioenergy not be defined and subsidized as renewable energy under the EU directive, citing growing scientific evidence that current EU bioenergy policy has done tremendous harm to people, forests and the climate."

 David Attenborough and Professor Brian Cox call for Major Program to Combat Climate Change
   In a 2-minute video, David Attenborough explains that our world and its wildlife are in danger because of climate change.  In the 1960s, scientists overcame immense odds to put men on the moon. A similar effort is now needed to combat climate change
Cartoon (left): Steve Sack, Star Tribute

Double global warming whammy from domestic wood heating and diesel particles
   A study in 2015 by a science team led by Los Alamos National Laboratory shows that the particulates found in urban smoke are especially prone to absorbing sunlight and having a heating effect on the planet. The new analysis demonstrates that wood burning emits organic species that coat soot particles produced by diesel combustion, creating a lens to focus sunlight and increase warming. The study also shows that the magnification is increased as the particles age and are coated with more airborne chemicals.
  “This is a double whammy,” said project leader Manvendra Dubey. “The transparent organics amplify soot’s warming by lensing, and then we have this very stable brown carbon that causes additional warming. We clearly elucidate the detailed processes that makes the carbon particle much more potent warming agents and provide a framework to capture them in climate models.”
   The researchers used state-of-the-art instruments in field studies near London tracking an urban plume as it moved across Europe. The observed lensing effect was successfully reproduced by theoretical calculations and laboratory measurements.
   The paper also underscored the need for multiple field studies in more diverse environments with mixed carbon sources. Dubey noted that a similar study published in the journal Science in 2012 saw no enhanced light absorption in soot particles in California in the summer. He said that the key difference is that the sampled region did not have the solid wood combustion that was pervasive in the United Kingdom during wintertime.

Climate Central Report - Pulp Fiction - The European Accounting Error That's Warming the Planet
The damaging effects of black carbon 23 Mar 2016. "The EPA report asserts that globally, the best strategies for reducing black carbon emissions include targeting brick kilns and coke ovens in Asia, and cookstoves and diesel vehicles everywhere."
Unaccounted for Arctic microbes appear to be speeding up glacier melting 23 Mar 2016.  "on a grainy, soil-like substance found on the surface of Arctic ice known as cryoconite, which is made of dust and industrial soot glued together by photosynthetic bacteria ...he bacterially-made granules self-regulate the depth and shape of these holes to maximise their exposure to sunlight, which in turn further melts the glacier's surface ice"
Risk of multiple tipping points should be triggering urgent action on climate change  21 Mar 2016. "multiple interacting climate tipping points could be triggered this century if climate change isn't tackled - leading to irreversible economic damages worldwide. Using a state-of-the-art model, the researchers studied the effects of five interacting tipping points on the global economy - including a collapse of the Atlantic overturning circulation, a shift to a more persistent El Nino regime, and a dieback of the Amazon rainforest.
The study showed that the possibility of triggering these future tipping points increased the present 'social cost of carbon' in the model by nearly eightfold - from US$15 per tonne of carbon dioxide emitted, to US$116/tCO2."
Dangerous global warming will happen sooner than thought  10 March 2016. "University of Queensland and Griffith University researchers have developed a “global energy tracker” which predicts average world temperatures could climb 1.5C above pre-industrial levels by 2020.  That forecast, based on new modelling using long-term average projections on economic growth, population growth and energy use per person, points to a 2C rise by 2030."

Greenpeace - Fuelling a Biomess 
• "Burning natural forest biomass – whether for electricity, heat or biofuels – is not carbon-neutral as governments and companies claim. 
"Burning trees contributes to climate change for decades, as shown by the most up-to-date science, until replacement trees fully grow back
• "Compared to current coal-fired electricity plants in North America, current woody biomass power plants can emit at the smokestack up to 150% more climate disrupting CO2, 400%more lung irritating carbon monoxide, and 200% more asthma causing particulate matter to produce the same amount of energy. The CO2 emited will harm climate for decades before being captured by regrowing trees.
• "Burning boreal biomass contributes to climate change through a long carbon payback 
time due to the slow regrowth of forests and the fragility of existing carbon stocks."

Assessment of urgent impacts of greenhouse gas emissions—the climate tipping potential (CTP)
The introduction to this paper explains: The global climate is changing these years, and we are quickly approaching expected climate tipping points (Hansen et al. 2008). A climate tipping point is a level of forcing in the climate system beyond which dramatic changes continue to occur without further forcing due to the initiation of positive feedback loops (Hansen et al. 2008; US DOT CCCEF 2009). Crossing such tipping points may lead to irreversible climate change

Conclusions: "The CTP (climate tipping potential) metric distinguishes different GHG (greenhouse gas) emission impacts in terms of their contribution to exceeding a short-term target and highlights their increasing importance when approaching a climatic target level, reflecting the increasing urgency of avoiding further GHG emissions in order to stay below the target level.” 

Relationship between methane and particle emissions in domestic wood heaters

John Gras's study (mainly of correctly-operated heaters) measured particle emissions from of emissions from Australian woodheaters burning both eucalype hardwoods and softwoods. 
    The results for eucyalypt hardwoods (see graph) were used by consultant Prof John Todd to derive an equation (CH4 = 1.495 x particle emissions) which is used by the Australian Greenhouse Office to estimate methane from particle emissions.
        For pine, the graph shows a combination of Australian and overseas results. In John Gras's Australian study  the AS4103 heater burning pine had average particle emissions of 15.8 grams per kg of wood burned and methane emissions of 30 grams per kg, equivalent to the global warming of 1.02 kg of carbon dioxide over 100 years and in the 20 years after emission of 2.58 kg CO2.  
     The average wood stove in Armidale burns about 4 tonnes of firewood per year.  One report suggested that the shortage of hardwood might be overcome by burning softwood.  However, this would be disastrous for the climate.  Including the global warming from methane, black carbon and carbon monoxide, a correctly-operated heater burning 4 tonnes of softwood per year would be expected to cause as much global warming over 20 years as the emission of 75 tonnes of CO2 equivalent to the global warming over 20 years from heating perhaps 40 similar houses in Armidale with an efficient reverse cycle electric heat pump using coal-fired power, or many more if a proportion of the power is generated by wind, solar or other renewables.

Black Carbon
    NASA scientists report that black carbon aerosols also cause global warming.  Sulphate aerosols scatter incoming solar radiation and cool the planet.  However, aerosols containing black carbon absorb incoming solar radiation and have a strong warming influence on the atmosphere.  Modelling suggest that black carbon aerosols account for 45% or more of the warming that has occurred in the Arctic during the last three decades.  Newspaper headlines announced: Al Gore calls on world to burn less wood and fuel to curb 'black carbon'

90 Scientists urge US Congress to improve carbon accounting for biofuels and bioenergy
"Clearing or cutting forests for energy, either to burn trees directly in power plants or to replace forests with bioenergy crops, has the net effect of releasing otherwise sequestered carbon into the atmosphere, just like the extraction and burning of fossil fuels.  Letter to Congress

Letter to the Washington State Legislature arguing that burning harvested trees that would otherwise remain standing instead of natural gas could lead to an increase in total carbon emissions.

Alternative clean, renewable energy

Photovoltaic systems for new houses.   New houses must be insulated and can be designed on passive solar principles so they need very little heating.  Armidale residents can currently install a 1.5 kW of solar cells for $3680.  This system is expected to generate 2.43 megwatt hours of electricity, more than enough to power a reverse cycle heat pump to meet the heating and lighting requirements of a well-designed passive solar house, so that, whatever the rise in electricity prices, the owners would never need to pay another electricity bill!
    Owners of new houses that aren't as well designed can still enjoy similar benefits by purchasing a larger system. 

Solar air heaters.   New houses can have roof-integrated solar air heaters.
Other houses can be retro-fitted with rooftop models, e.g. the commercially available models from T3E energy.  A US company produces a do-it yourself model.  Plans for self-build models are also available on the web, e.g. in mother earth newsMark Bower's design, or one made from recycled aluminium cans.  It is possible that some of these ideas might be improved for Australian conditions by using dark colorbond instead of 2 layers of black aluminium window screen.

Install rooftop PV solar cells - cheaper and cleaner than woodheating

        Other environmentally friendly options include offsetting electricity costs and greenhouse gas emissions by installing a photovoltaic system on the roof.  Local suppliers include "Farming the sun, New England", who can supply a  1.5 kW system for $3680, comparable to the cost of a new woodheater (see right panel) and New England Solar Power.  As well as paying for itself in 2.5 years,  as long as ceiling insulation and draftproofing have been installed, the system should almost totally offset the greenhouse gas emissions and costs of reverse cycle electric or gas heating.
        Householders should also consider taking advantage of Armidale's lovely sunny winter climate by installing solar air heating so that no heating is needed on most days during daylight hours and for a couple of hours into the early evening.

Interesting/useful links

IPCC - Intergovernmental Panel on Climate Change
L.A. Times cuts off climate-change deniers

The Most Interesting Climate Policy Debate You Haven't Heard Of - Debate for conservatives, organized by conservatives, featuring two climate-science deniers, James Taylor and David Kreutzer in front of a largely conservative audience.  Yet, at the conclusion of the debate, a straw poll was taken and approximately 80% of the audience indicated they favored taxing carbon emissions in return for a dollar-for-dollar tax swap on something else (FICA taxes, corporate income taxes, etc).
Canada's Black Carbon Inventory In 2013, approximately 45 000 tonnes (45 kilotonnes) of black carbon were emitted in Canada. The transportation sector (65%), residential wood burning (26%), upstream oil and gas industries (8%) and other industrial sources (1%), were Canada’s primary sources of human-caused black carbon emissions in Canada.
How Europe’s climate policies led to more U.S. trees being cut down A number of independent experts and scientific studies including an analysis released in May 2015 are casting doubt on a key argument used to justify the cutting of Southern forests to make fuel. In reality, these scientists say, Europe’s appetite for wood pellets could lead to more carbon pollution for decades to come, while also putting some of the East Coast’s most productive wildlife habitats at risk. Scientists fly glacial ice to south pole to unlock secrets of global warming. As ice forms on a glacier, it encloses small bubbles of air that contain a sample of the atmosphere at that time. From these samples, scientists can measure atmospheric concentrations of gases such as carbon dioxide and methane over periods that range from hundreds to tens of thousands of years into the past. In order to retain this information, ice cores are being extracted and flown to a specially constructed vault at the French-Italian Concordia research base, 1,000 miles from the south pole.
Current atmospheric models underestimate the dirtiness of Arctic air Black carbon aerosols are important for understanding climate change. Unfortunately, current simulation models consistently underestimate the amount of these aerosols in the Arctic compared to actual measurements.
Guardian, 2011: Wood fires fuel climate change – UN
Thinkprogress, 2015: How The EPA And New York Times Are Getting Methane All Wrong
Geophysical Research Letters article, Dec 2017 - Methane causes 20‐25% more warming than previously thought.
Wood Burning, Biomass, Air Pollution, and Climate Change by Christopher D. Ahlers "In labeling wood burning as a source of “renewable energy,” consumers and corporations have overlooked a more compelling and immediate health problem. Worldwide, air pollution causes the deaths of approximately seven million people every year, far more than the number of deaths from climate change. Mortality is largely due to air emissions of fine particulate matter. Given the popularity of burning wood and regulatory loopholes, the public health effects of air pollution go underregulated, and often unregulated. As a source of energy that is generated by combustion and results in the direct emission of fine particulates, biomass is like coal, oil, and natural gas (non-renewable energy), and unlike solar and wind (renewable energy)."  
Quote from paper:  "In theory, nuclear power is far more “renewable” than biomass, yet it is denied the “renewability” label because of the fear of health and environmental impacts. There is no reason why this reasoning should not also extend to biomass and wood burning, given the nature of the air pollutants (criteria pollutants and hazardous air pollutants) and their adverse impacts on public health."
Is Biomass Energy Renewable?  discussion of some of the ideas in Dr Ahlers' report.