Response to Comment on "The global tree restoration potential".

Our study quantified the global tree restoration potential and its associated carbon storage potential under existing climate conditions. Skidmore dispute our findings, using as reference a yearly estimation of carbon storage that could be reached by 2050. We provide a detailed answer highlighting misunderstandings in their interpretation, notably that we did not consider any time limit for the restoration process.

Response to Comments on "The global tree restoration potential".

Our study quantified the global tree restoration potential and its associated carbon storage potential under existing climate conditions. We received multiple technical comments, both supporting and disputing our findings. We recognize that several issues raised in these comments are worthy of discussion.

The global tree restoration potential.

The restoration of trees remains among the most effective strategies for climate change mitigation. We mapped the global potential tree coverage to show that 4.4 billion hectares of canopy cover could exist under the current climate.

The extent of forest in dryland biomes.

Dryland biomes cover two-fifths of Earth's land surface, but their forest area is poorly known. Here, we report an estimate of global forest extent in dryland biomes, based on analyzing more than 210,000 0.5-hectare sample plots through a photo-interpretation approach using large databases of satellite imagery at (i) very high spatial resolution and (ii) very high temporal resolution, which are available through the Google Earth platform.

Financing and current capacity for REDD+ readiness and monitoring, measurement, reporting and verification in the Congo Basin.

This paper provides the first critical analysis of the financing and current capacity for REDD+ readiness in the Congo Basin, with a particular focus on the REDD+ component of national forest monitoring and measurement, reporting and verification (M&MRV). We focus on three areas of analysis: (i) general financing for REDD+ readiness especially M&MRV; (ii) capacity and information for REDD+ implementation and M&MRV; (iii) prospects and challenges for REDD+ and M&MRV readiness in terms of financing and capacity. For the first area of analysis, a REDD+ and M&MRV readiness financing database was created based on the information from the REDD+ voluntary database and Internet searches.

Options for monitoring and estimating historical carbon emissions from forest degradation in the context of REDD+.

Measuring forest degradation and related forest carbon stock changes is more challenging than measuring deforestation since degradation implies changes in the structure of the forest and does not entail a change in land use, making it less easily detectable through remote sensing. Although we anticipate the use of the IPCC guidance under the United Framework Convention on Climate Change (UNFCCC), there is no one single method for monitoring forest degradation for the case of REDD+ policy. In this review paper we highlight that the choice depends upon a number of factors including the type of degradation, available historical data, capacities and resources, and the potentials and limitations of various measurement and monitoring approaches.

Options for sampling and stratification for national forest inventories to implement REDD+ under the UNFCCC.

Background: Developing countries that are willing to participate in the recently adopted (16th Session of the Conference of Parties (COP) in Cancun) mitigation mechanism of Reducing emissions from Deforestation and Forest Degradation - and the role of conservation, sustainable management of forests and enhancement of forest carbon stocks (REDD+) - will have to establish a national forest monitoring system in order to assess anthropogenic forest-related greenhouse gas emissions by sources and removals by sinks. Such a system should support the Measurement, Reporting and Verification (MRV) requirement of the United Nations Framework Convention on Climate Change (UNFCCC) as the REDD+ mechanism is results-based. A national forest inventory (NFI) is one potential key component of such an MRV system.

The effect of climate anomalies and human ignition factor on wildfires in Russian boreal forests.

Over the last few years anomalies in temperature and precipitation in northern Russia have been regarded as manifestations of climate change. During the same period exceptional forest fire seasons have been reported, prompting many authors to suggest that these in turn are due to climate change. In this paper, we examine the number and areal extent of forest fires across boreal Russia for the period 2002-2005 within two forest categories: 'intact forests' and 'non-intact forests'.

Ecology: human role in Russian wild fires.

Anomalies in temperature and precipitation in northern Russia over the past few years have been viewed as manifestations of anthropogenic climate change, prompting suggestions that this may also account for exceptional forest fires in the region. Here we examine the number of forest-fire events across the boreal Russian Federation for the period 2002 to 2005 in 'intact' forests, where human influence is limited, and in 'non-intact' forests, which have been shaped by human activity. Our results show that there were more fires in years during which the weather was anomalous, but that more than 87% of fires in boreal Russia were started by people.