Search results for "kasvihuonekaasut"

Ecosystem carbon response of an Arctic peatland to simulated permafrost thaw

2019

Permafrost peatlands are biogeochemical hot spots in the Arctic as they store vast amounts of carbon. Permafrost thaw could release part of these long-term immobile carbon stocks as the greenhouse gases (GHGs) carbon dioxide (CO 2 ) and methane (CH 4 ) to the atmosphere, but how much, at which time-span and as which gaseous carbon species is still highly uncertain. Here we assess the effect of permafrost thaw on GHG dynamics under different moisture and vegetation scenarios in a permafrost peatland. A novel experimental approach using intact plant–soil systems (mesocosms) allowed us to simulate permafrost thaw under near-natural conditions. We monitored GHG flux dynamics via high-resolution…

Large stocks of peatland carbon and nitrogen are vulnerable to permafrost thaw

2020

Significance Over many millennia, northern peatlands have accumulated large amounts of carbon and nitrogen, thus cooling the global climate. Over shorter timescales, peatland disturbances can trigger losses of peat and release of greenhouses gases. Despite their importance to the global climate, peatlands remain poorly mapped, and the vulnerability of permafrost peatlands to warming is uncertain. This study compiles over 7,000 field observations to present a data-driven map of northern peatlands and their carbon and nitrogen stocks. We use these maps to model the impact of permafrost thaw on peatlands and find that warming will likely shift the greenhouse gas balance of northern peatlands. …

CH4 oxidation in a boreal lake during the development of hypolimnetic hypoxia

2020

AbstractFreshwater ecosystems represent a significant natural source of methane (CH4). CH4 produced through anaerobic decomposition of organic matter (OM) in lake sediment and water column can be either oxidized to carbon dioxide (CO2) by methanotrophic microbes or emitted to the atmosphere. While the role of CH4 oxidation as a CH4 sink is widely accepted, neither the magnitude nor the drivers behind CH4 oxidation are well constrained. In this study, we aimed to gain more specific insight into CH4 oxidation in the water column of a seasonally stratified, typical boreal lake, particularly under hypoxic conditions. We used 13CH4 incubations to determine the active CH4 oxidation sites and the …

The emission reduction potential of electric transport modes in Finland

2021

The transportation sector has become the fastest growing source of greenhouse gas (GHG) emissions. One solution to mitigate the impacts is a shift towards electric modes. Where previous studies have only focused on the replacement of individual modes, our study presents a more holistic approach by comparing land-based, water-based and airborne transportation modes. We study the GHG emission reduction potentials of electric cars, buses, trains, ferries and aircraft in comparison to existing modes on 34 routes within Finland and across the Baltic Sea to Sweden and Estonia. By comparing the GHG emissions in carbon dioxide equivalents (CO2-eq) per passenger kilometer for each mode, we also cons…

Biomass gasification to heat, electricity and biofuels : HighBio project publication

2011

Biomassan kaasutus sähköksi, lämmöksi ja biopolttoaineiksi : HighBio-projektijulkaisu

2011

Biomass to energy and chemicals : HighBio2 project publication

2013

The emission reduction potentials of First Generation Electric Aircraft (FGEA) in Finland

2020

Under the looming climate crisis, aviation needs to find new solutions to cut its greenhouse gas emissions. One pathway towards zero emissions is the use of electric aircraft. While current battery technology will not allow for medium and long-haul flights at full capacity, on short-haul routes First Generation Electric Aircraft (FGEA) could play a significant role in the near future. Current FGEA under development could carry 9–19 passengers on distances of 400–1046 km by 2025. This study focuses on the emissions reduction potentials of FGEA in Finland. It compares the carbon dioxide equivalent (CO2-eq) emissions and real travel times (RTT) from door-to-door of FGEA on 47 routes with exist…

Förgasning av biomassa till värme, elektricitet och biobränslen : publikation för HighBio-projektet

2011

Statistical upscaling of ecosystem CO2 fluxes across the terrestrial tundra and boreal domain: Regional patterns and uncertainties

2021

The regional variability in tundra and boreal carbon dioxide (CO2) fluxes can be high, complicating efforts to quantify sink-source patterns across the entire region. Statistical models are increasingly used to predict (i.e., upscale) CO2 fluxes across large spatial domains, but the reliability of different modeling techniques, each with different specifications and assumptions, has not been assessed in detail. Here, we compile eddy covariance and chamber measurements of annual and growing season CO2 fluxes of gross primary productivity (GPP), ecosystem respiration (ER), and net ecosystem exchange (NEE) during 1990–2015 from 148 terrestrial high-latitude (i.e., tundra and boreal) sites to a…