Canadian boreal forests and climate change mitigation1

There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

Abstract

Related collections

Most cited references 239

Record: found
Abstract: found
Article: not found

Greenhouse-gas emission targets for limiting global warming to 2 degrees C.

Malte Meinshausen, Nicolai Meinshausen, William Hare … (2009)

More than 100 countries have adopted a global warming limit of 2 degrees C or below (relative to pre-industrial levels) as a guiding principle for mitigation efforts to reduce climate change risks, impacts and damages. However, the greenhouse gas (GHG) emissions corresponding to a specified maximum warming are poorly known owing to uncertainties in the carbon cycle and the climate response. Here we provide a comprehensive probabilistic analysis aimed at quantifying GHG emission budgets for the 2000-50 period that would limit warming throughout the twenty-first century to below 2 degrees C, based on a combination of published distributions of climate system properties and observational constraints. We show that, for the chosen class of emission scenarios, both cumulative emissions up to 2050 and emission levels in 2050 are robust indicators of the probability that twenty-first century warming will not exceed 2 degrees C relative to pre-industrial temperatures. Limiting cumulative CO(2) emissions over 2000-50 to 1,000 Gt CO(2) yields a 25% probability of warming exceeding 2 degrees C-and a limit of 1,440 Gt CO(2) yields a 50% probability-given a representative estimate of the distribution of climate system properties. As known 2000-06 CO(2) emissions were approximately 234 Gt CO(2), less than half the proven economically recoverable oil, gas and coal reserves can still be emitted up to 2050 to achieve such a goal. Recent G8 Communiqués envisage halved global GHG emissions by 2050, for which we estimate a 12-45% probability of exceeding 2 degrees C-assuming 1990 as emission base year and a range of published climate sensitivity distributions. Emissions levels in 2020 are a less robust indicator, but for the scenarios considered, the probability of exceeding 2 degrees C rises to 53-87% if global GHG emissions are still more than 25% above 2000 levels in 2020.

0 comments Cited 700 times – based on 0 reviews      Review now

Bookmark

Record: found
Abstract: found
Article: not found

Old-growth forests as global carbon sinks.

Sebastiaan Luyssaert, E Detlef Schulze, Annett Börner … (2008)

Old-growth forests remove carbon dioxide from the atmosphere at rates that vary with climate and nitrogen deposition. The sequestered carbon dioxide is stored in live woody tissues and slowly decomposing organic matter in litter and soil. Old-growth forests therefore serve as a global carbon dioxide sink, but they are not protected by international treaties, because it is generally thought that ageing forests cease to accumulate carbon. Here we report a search of literature and databases for forest carbon-flux estimates. We find that in forests between 15 and 800 years of age, net ecosystem productivity (the net carbon balance of the forest including soils) is usually positive. Our results demonstrate that old-growth forests can continue to accumulate carbon, contrary to the long-standing view that they are carbon neutral. Over 30 per cent of the global forest area is unmanaged primary forest, and this area contains the remaining old-growth forests. Half of the primary forests (6 x 10(8) hectares) are located in the boreal and temperate regions of the Northern Hemisphere. On the basis of our analysis, these forests alone sequester about 1.3 +/- 0.5 gigatonnes of carbon per year. Thus, our findings suggest that 15 per cent of the global forest area, which is currently not considered when offsetting increasing atmospheric carbon dioxide concentrations, provides at least 10 per cent of the global net ecosystem productivity. Old-growth forests accumulate carbon for centuries and contain large quantities of it. We expect, however, that much of this carbon, even soil carbon, will move back to the atmosphere if these forests are disturbed.

0 comments Cited 436 times – based on 0 reviews      Review now

Bookmark

Record: found
Abstract: found
Article: not found

The effect of permafrost thaw on old carbon release and net carbon exchange from tundra.

Edward A G Schuur, Jason G. Vogel, Kathryn Crummer … (2009)

Permafrost soils in boreal and Arctic ecosystems store almost twice as much carbon as is currently present in the atmosphere. Permafrost thaw and the microbial decomposition of previously frozen organic carbon is considered one of the most likely positive climate feedbacks from terrestrial ecosystems to the atmosphere in a warmer world. The rate of carbon release from permafrost soils is highly uncertain, but it is crucial for predicting the strength and timing of this carbon-cycle feedback effect, and thus how important permafrost thaw will be for climate change this century and beyond. Sustained transfers of carbon to the atmosphere that could cause a significant positive feedback to climate change must come from old carbon, which forms the bulk of the permafrost carbon pool that accumulated over thousands of years. Here we measure net ecosystem carbon exchange and the radiocarbon age of ecosystem respiration in a tundra landscape undergoing permafrost thaw to determine the influence of old carbon loss on ecosystem carbon balance. We find that areas that thawed over the past 15 years had 40 per cent more annual losses of old carbon than minimally thawed areas, but had overall net ecosystem carbon uptake as increased plant growth offset these losses. In contrast, areas that thawed decades earlier lost even more old carbon, a 78 per cent increase over minimally thawed areas; this old carbon loss contributed to overall net ecosystem carbon release despite increased plant growth. Our data document significant losses of soil carbon with permafrost thaw that, over decadal timescales, overwhelms increased plant carbon uptake at rates that could make permafrost a large biospheric carbon source in a warmer world.

0 comments Cited 374 times – based on 0 reviews      Review now

Bookmark

All references

Author and article information

Journal

Title: Environmental Reviews

Abbreviated Title: Environ. Rev.

Publisher: Canadian Science Publishing

ISSN (Print): 1181-8700

ISSN (Electronic): 1208-6053

Publication date Created: December 2013

Publication date (Print): December 2013

Volume: 21

Issue: 4

Pages: 293-321

Article

DOI: 10.1139/er-2013-0039

SO-VID: 4ddbc49f-8b38-47ef-8df2-3322d7de1d57

History

Data availability:

Comments

Comment on this article

scite_

Cited by 49

See all cited by

Most referenced authors 2,647

See all reference authors

Canadian boreal forests and climate change mitigation1

Read this article at

Abstract

Related collections

Climate Change: Open Access

Most cited references 239

Greenhouse-gas emission targets for limiting global warming to 2 degrees C.

Old-growth forests as global carbon sinks.

The effect of permafrost thaw on old carbon release and net carbon exchange from tundra.

Author and article information

Journal

Article

History

Comments

Comment on this article

Similar content 2,850

Cited by 49

Most referenced authors 2,647