Divisjon for skog og utmark
NCS-REVISE - Revising the climate change mitigation potential of natural climate solutions
Slutt: des 2028
Start: des 2024
Mange land tar sikte på å nå sine klimamål ved å øke karbonopptaket i skog, enten gjennom å utvide skogarealer eller ved å gjenopprette bærekraftig skogforvaltning i dårlig forvaltede skoger. Det er økende vitenskapelig enighet om potensialet til slike landbaserte tiltak, kjent som «naturlige klimaløsninger» (Natural Climate Solutions, NCS), til å bidra til å dempe klimaendringene ved å fjerne ekstra karbondioksid fra atmosfæren.
Prosjektmedarbeidere
Rosie Fisher Benjamin Sanderson Kjetil Schanke Aas Norman Steinert Jessica Needham Erik Kusch| Status | Pågående |
| Start- og sluttdato | 31.12.2024 - 30.12.2028 |
| Prosjektansvarlig, NIBIO | Ryan Bright |
| Divisjon | Divisjon for skog og utmark |
| Avdeling | Skogforvaltning |
Disse tiltakene påvirker imidlertid ikke bare karbonkretsløpet, men også utvekslingen av vann, energi og andre organiske forbindelser mellom land og atmosfære. Disse interaksjonene endrer både temperaturen og bevegelsene i jordens atmosfære på måter som enten kan forsterke eller redusere fordelene ved økt karbonopptak.
Dersom man overser disse andre viktige mekanismene, kan det føre til klimapolitikk som er suboptimal eller til og med motvirker sin hensikt.
NCS-REVISE har som mål å kvantifisere disse ofte oversette klimadrivkreftene knyttet til storskala implementering av NCS, og dermed revidere dagens estimater av klimatiltakenes potensial, som i hovedsak fokuserer på fordelene for karbonkretsløpet alene. Prosjektet samler forskere innen land- og atmosfærefag for å tette dette kunnskapsgapet ved å: Bruke avanserte globale klimamodeller og analytiske verktøy for å kvantifisere disse tilleggseffektene på klimaet knyttet til NCS; Anvende innovative analysemetoder for å bygge forståelse av spesifikke klimadrivkrefter, deres koblinger til endringer i overflateegenskaper og prosesser, deres tidslige og romlige mønstre og usikkerheter under klimaendringer, samt deres potensial til å påvirke klimaet andre steder; Utvikle nye verktøy for å knytte spesifikke klimadrivkrefter til bestemte typer NCS og geografiske regioner.
Gjennom dette arbeidet vil NCS-REVISE gi en mer helhetlig vurdering av klimaeffektene av naturlige klimaløsninger, og dermed legge til rette for utviklingen av mer effektive og helhetlige klimatiltak.
Publikasjoner i prosjektet
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
The top‐of‐atmosphere (TOA) albedo controls the amount of solar energy absorbed by Earth and is influenced by the reflectivity of both the atmosphere and surface. With considerable changes in land use over the past few decades it is reasonable to question whether a perturbed surface albedo has influenced TOA albedo over the corresponding period. Here, we identify regions for which surface albedo changes have been the dominant driver of TOA albedo trends from 2001 to 2020 and examine the degree to which this relates to changes in snow cover, surface soil moisture, and vegetation density and greenness. We show that land surface albedo changes have been the dominant driver of TOA albedo trends in 10.0% of the global land area, within which surface albedo decreases have led to increases in absorbed solar radiation of 0.737 ± 4.984 Wm −2 from 2001 to 2020. This corresponds to global change in absorbed solar radiation of 0.019 ± 0.812 Wm −2 , which is equivalent to approximately 7.0% of the radiative forcing from anthropogenic CO 2 emissions from 2011 to 2019 (IPCC, 2021, https://doi.org/10.1017/9781009157896.009 ). Net TOA darkening above tundra and deserts constitutes 38.6% and 21.4%, respectively, to the radiative feedback identified, whereas temperate biomes induced net TOA brightening, corresponding to 22.3%. Collectively, changes in snow cover, vegetation density and greenness, and surface soil moisture drive 68.5% of the surface albedo changes. The importance of surface albedo in explaining TOA albedo trends for parts of the globe highlights the relevance of land surface changes in understanding Earth's energy imbalance.
Sammendrag
ire has the immediate effect that roughly half of carbon and nitrogen is emitted and lost from forest floors, that the remaining ashes fertilize the ground and pools of dead organic matter and stable black carbon is produced. Depending on the intensity of the fire it will potentially have long lasting physical, chemical and biological effects. Fire as a disturbance agent to the forest floor has acted on the forest landscapes in Scandinavia since the last glaciation as a natural phenomenon and as a result of human activities. Fires have likely occurred in all forests in Norway even though sampling and dating of charcoal in selected landscapes indicate a lower frequency along the west coast than in the southeastern forest region and in neighboring Sweden. Where the availability of synthetic fertilizers in agriculture (ca. 1900) and the significance of timber value and -trade (ca. 1700) mark important shifts in fire occurrence and avoidance, forest fires have been successfully suppressed with documented effects since the 1970’s likely leading to an accumulation of forest floor organic matter. Using a one-time survey of >8000 registrations of the thickness of the forest floor, its sub-layers, humus form and the occurrence of charcoal in upland forests of the Norwegian National Forest Inventory, we investigate the regional distribution of charcoal occurrence in upland forests indicating earlier fire activity and look for legacies on carbon stocks or forest floor characteristics using available national soil survey data. Forest floors in boreal and cold temperate forests hold 30-60% of total forest soil carbon stocks equivalent in magnitude to that held by the living biomass of trees. Thus, we further estimate the areas and forest floor carbon stocks most likely to gain increased vulnerability to fire under future climate conditions.
Forfattere
Lucas K. Johnson Zhiqiang Yang Angela Erb Ryan Bright Grant M. Domke Tracey S. Frescino Crystal B. Schaaf Sean P. HealeySammendrag
Reforestation is generally regarded as having the most substantial climate mitigation potential among a suite of available natural climate solutions which have focused almost exclusively on the benefits of carbon sequestration and storage. However, these reforestation studies have not accounted for the adverse warming impacts resulting from corresponding surface albedo change. A newly available dataset developed with albedo imagery from the Landsat 8 satellite analyzed at field plots from the United States (US) Forest Inventory and Analysis (FIA) program provides non-soil carbon stocks and corresponding carbon-equivalent albedo offsets for 30 distinct forest-type groups indexed by 10-year age bins. In this case study we leverage this new dataset in concert with FIA species distribution data to investigate reforestation scenario planning based on joint carbon-albedo estimates (non-soil carbon stock less a carbon-equivalent albedo offset) instead of just carbon storage estimates alone. Specifically, our analysis informs managers interested in planting optimal forest-type groups for climate change mitigation outcomes approaching the year 2050. We assist in one of the most fundamental steps in any reforestation project: deciding which forest type or tree species mix to plant. We present our results as forest-type group recommendations within 64,000 hectare hexagons as a means to offer localized guidance and to examine the spatial patterns of albedo impacts across the conterminous US. We found that albedo offsets were most impactful on decisions in the Northeastern regions of the US, where optimizing for joint carbon-albedo in the next 25-years implies planting deciduous forest-type groups (Maple/beech/birch) instead of otherwise carbon-optimal coniferous forest-type groups (White/red/jack pine). Although the consideration of albedo did not alter 25-year tree planting decisions in most of the US, it did reduce the expected climate benefit of reforestation in general. We provide a standalone application that ranks all forest-type groups detected by FIA within a given hexagon, allowing managers to evaluate alternatives in light of site-specific constraints. This paper describes a replicable case study for incorporating albedo offsets in reforestation plans. Similar analyses may be performed anywhere Landsat albedo data are available over adequate measurements of forest carbon stocks. Recommendations: • Albedo impacts on 25-year tree planting decisions are concentrated in the Northeastern regions of the United States, where considering albedo offsets together with carbon stocks implies planting the Maple/beech/birch forest-type group in place of the otherwise carbon-optimal White/red/jack pine group. • Our reforestation support application allows managers to explore localized forest-type group rankings on the basis of joint carbon-albedo benefits. • Fine-resolution albedo data, which is not currently a standard data product, provides more comprehensive support for reforestation projects intended to mitigate global climate change.
Forfattere
Sean P Healey Zhiqiang Yang Angela M Erb Ryan Bright Grant M Domke Tracey S Frescino Crystal B SchaafSammendrag
Rapidly maturing frameworks for investing in and committing to mitigation of climate change through forest management have focused almost exclusively on the benefits of carbon sequestration, without accounting for collateral changes in geophysical factors such as surface albedo. Newly available 30 m albedo retrievals derived from imagery acquired by the Landsat 8 satellite, analyzed at 273 652 field plots monitored by the United States Forest Service, suggest that large areas of the US Inter-Mountain West’s forests have a net warming impact on the planet’s surface energy balance. For the conterminous US, the impacts of albedo offset approximately half of the recognized non-soil forest carbon storage benefit. The emerging capacity to resolve albedo evolution at the scale of a large number of inventory plots also provides unprecedented empirical evidence that albedo impacts vary strongly as a function of both tree age and species group. This research highlights a correctable source of uncertainty in operational monitoring of forest-climate interactions, and it may temper expectations for forest establishment as a means of mitigating global climate change.
Sammendrag
Large‐scale re‐/afforestation projects afford sizable atmospheric CO2 removals yet questionsloom surrounding their potentially offsetting biogeophysical radiative forcings. Forest area change alters notonly the surface albedo but also heat, moisture, and momentum fluxes, which in turn modify the atmosphere'sradiative, thermodynamical, and dynamical properties. These so‐called radiative forcing “adjustments” havebeen little examined in re‐/afforestation contexts, and many questions remain surrounding their relevance inrelation to the instantaneous forcing from the surface albedo change—and whether they can affect Earth'sradiative energy balance in regions remote from where the re‐/afforestation occurs. Here, we quantifiedbiogeophysical radiative forcings and adjustments from realistically scaled re‐/afforestation in Europe at highspatial resolution and found that adjustments with high signal‐to‐noise were largely confined to only a fewmonths and to the region of re‐/afforestation. Adjustments were dominated by perturbed low‐level clouds andrarely exceeded ±25% of the annual albedo change forcing.