UVicSpace : Browsing by Subject "#science brief"

Browsing by Subject "#science brief"

Now showing 1 - 20 of 26

PCIC science brief: Climate impacts on specialty fruit and grazing in the Pacific Northwest
(Pacific Climate Impacts Consortium (PCIC), 2018-03) Pacific Climate Impacts Consortium (PCIC)
Two recent articles in the journal Climatic Change examine some of the effects that climate change may have on agriculture in the Pacific Northwest. Focusing on specialty fruit production, Houston et al. (2018) find that overall warmer conditions and reduced water availability may reduce net returns on crops due to increasing farming costs, affecting yields and altering product quality. They suggest that management strategies currently employed in marginal production areas that moderate temperatures and offset mismatches between the needs of the plant at various growth stages and seasonal weather conditions may be useful adaptation strategies. Neibergs and colleagues (2018) review the impacts of climate change on beef cattle production. They find that changes to seasonal temperature and precipitation may affect the availability of the plants on which cattle forage. This in turn could affect the number of cattle that an area can support, and the dates at which cattle are "turned-out" to pasture and taken in from pasture.
PCIC science brief: Climate model genealogy and its relationship to modelled climate properties
(Pacific Climate Impacts Consortium (PCIC), 2024-07) Pacific Climate Impacts Consortium (PCIC)
This Science Brief covers a recent paper in the Journal of Advances in Modeling Earth Systems that examines to what extent shared components and computer code between models affects their simulated climate sensitivities, feedbacks and resulting projections of surface air temperature. It finds that models with shared code tend to have greater similarity in their climate sensitivities, strengths of feedbacks, and therefore in their projected surface temperatures. The authors also demonstrated that weighting ensembles of models according to their family resemblance resulted in a lower equilibrium climate sensitivity than when using a simple ensemble mean, and also reduced differences in climate sensitivity between the two most recent generations of climate models. \
PCIC science brief: Human-induced greening of the northern extratropical land surface
(Pacific Climate Impacts Consortium (PCIC), 2017-01) Pacific Climate Impacts Consortium (PCIC)
This Science Brief covers recent research by Mao et al. (2016) published in Nature Climate Change. The authors find that the observed greening of the land surface between 30-75° north over the 1982-2011 period is largely due to anthropogenic greenhouse gas emissions.
PCIC science brief: Observed increases in extreme fire weather driven by humidity and temperature
(Pacific Climate Impacts Consortium (PCIC), 2023-06) Pacific Climate Impacts Consortium (PCIC)
This Science Brief covers a paper published in Nature Climate Change that uses reanalysis data to examine extreme fire weather and the conditions that drive it over the 1979-2020 period. The paper shows that temperature and relative humidity are driving observed global trends of increased fire weather. In this Science Brief we discuss what these results tell us about changes to fire weather in our province and across Canada.
PCIC science brief: On changes to glaciers in Western Canada
(Pacific Climate Impacts Consortium (PCIC), 2016-03) Pacific Climate Impacts Consortium (PCIC)
The new Science Brief covers two recent papers by Beedle et al. (2015) and Clarke et al. (2015) on changes to glaciers in western Canada. Publishing in the journal The Cryosphere, Beedle et al. use photographic methods to quantify changes to 33 glaciers in the Cariboo Mountains. They find that all of the glaciers receded over the 1952-2005 period with an average loss in surface area of about 0.19% per year. Clarke et al.'s work is published in Nature Geoscience and uses a regional glaciation model driven by global climate model output to examine possible future changes to glaciers in western Canada. Their projections show a reduction of between 70% to 95% in both glacier area and volume by the year 2100 compared to 2005.
PCIC science brief: On cloud-circulation coupling and climate sensitivity
(Pacific Climate Impacts Consortium (PCIC), 2023-06) Pacific Climate Impacts Consortium (PCIC)
One of the key uncertainties in climate model simulations has to do with the response of low-lying marine clouds to increasing temperatures. A recent paper in the journal Nature uses a mix of radar, lidar and data from atmospheric probes to test one of the mechanisms by which cloud cover is projected to be reduced under climate change. Their findings show that this mechanism is not evident in the trade wind regions, which suggests that might not occur in nature. This further suggests that the most extreme estimates of the climate's response to greenhouse gas emissions are less likely than earlier research suggests. Here we discuss what these results tell us about changes to the Earth's sensitivity to greenhouse gas emissions and what this may mean for our province.
PCIC science brief: On Paris climate accord emissions and temperature limits
(Pacific Climate Impacts Consortium (PCIC), 2018-08) Pacific Climate Impacts Consortium (PCIC)
The 2015 Paris Climate Accord aims to limit global warming to at most 2 °C and ideally 1.5 °C relative to the preindustrial climate, to limit the impacts of anthropogenic climate change. In this Science Brief, we discuss greenhouse gas emissions budgets and pathways consistent with these warming limits. Three recent papers in Nature Climate Change examine different aspects of these budgets and pathways: Tokarska and Gillett (2018) use global climate model projections to calculate a new carbon budget for future emissions, relative to the 2006-2015 period, that is consistent with keeping warming to 1.5 °C. They find a median remaining carbon budget of 208 billion tonnes from January 2016. Tanaka and O'Neill (2018) use an integrated assessment model to test whether the Paris temperature limits of 2 °C and 1.5 °C require zero greenhouse gas emissions, whether a zero net greenhouse emissions limit implies that the temperature limits will be met and what the effect of imposing both emissions and temperature limits are. Their results suggest that meeting the temperature limits doesn't require reducing net greenhouse gas emissions to zero, that reducing emissions to zero doesn't necessarily result in keeping temperatures under the Paris temperature limits by the end of the century, and that the effect of imposing both temperature and emissions limits is that temperatures decline after meeting the initial temperature limit. Van Vuuren et al. also use an integrated assessment model, to develop alternative emissions scenarios that examine how the need for negative emissions may be reduced through implementing other strategies, such as making large-scale lifestyle changes, shifting to renewable energy and switching to more efficient technologies for the production of energy and materials. They find that these strategies can reduce to a small degree, but not eliminate, the need for negative emissions. They also find that these measures have co-benefits such as helping to meet other United Nations sustainability goals.
PCIC science brief: On the Canadian precipitation analysis
(Pacific Climate Impacts Consortium (PCIC), 2019-02) Pacific Climate Impacts Consortium (PCIC)
Real-time precipitation data can be of use to areas ranging from forecasting to forest fire management. This Science Brief covers a recent paper that examines the past ten years of a near real-time Canadian precipitation product. Writing in Atmosphere-Ocean, Fortin et al. (2018) examine the Canadian Precipitation Analysis (CaPA), a near real-time precipitation product covering all of North America that is produced by Environment and Climate Change Canada. They review papers that evaluate CaPA compared to precipitation observations as well as the applications of CaPA for various types of research, ranging from hydrology1 and hydrometeorology2 to biogeophysics3. They find that CaPA compares favourably against other precipitation data, and report that it has been used successfully in studies across a number of fields, including hydrometeorology, hydrology, land surface and atmospheric modelling.
PCIC science brief: On the loss of CO₂ in the winter observed across the Northern permafrost region
(Pacific Climate Impacts Consortium (PCIC), 2020-05) Pacific Climate Impacts Consortium (PCIC)
As the Arctic warms, the rate at which microbes in Arctic soil digest soil organic matter increases and, with it, the release of carbon dioxide into the atmosphere also increases. The amount of carbon released into the atmosphere from permafrost in this region is significant and so it is important to measure it accurately and be able to make credible projections of it. Publishing in Nature Climate Change, Natali et al. (2019) use observations of CO2 flux from Arctic and Boreal permafrost soil to create a model that allows them to estimate winter (October through the end of April) soil carbon flux over the 2003-2017 period. They also drive their model with global climate model output, to make projections of future CO2 flux in the region. They estimate that approximately 1.7 gigatonnes of carbon (GtC) were released each winter over the 2003-2017 period. The authors also find that, of the variables that they tested, soil temperature had the largest relative influence on CO2 flux. Their projections show future winter Arctic soil fluxes of about 2.0 GtC per year by 2100, for a moderate emissions scenario, and about 2.3 GtC per year, assuming a high-emissions scenario.
PCIC science brief: On the promise of biomass and biosphere-climate interactions
(Pacific Climate Impacts Consortium (PCIC), 2015-04) Pacific Climate Impacts Consortium (PCIC)
Two articles recently published in the peer-review literature seek to answer two related questions: What role could utilizing vegetation burning for energy, with methods to capture the carbon dioxide emitted, have in aggressive short-term climate mitigation in western North America? And, how might North American vegetation and its interactions with the climate change in the future? Addressing the first question in Nature Climate Change, Sanchez et al. (2015) find that western North America could attain a carbon-negative power system by 2050 through strong deployment of renewable energy sources, including BioEnergy with Carbon Capture and Storage (BECCS), and fossil fuel reductions. Their results indicate that reductions of up to 145% from 1990s emissions are possible. They also find that the primary value of BECCS is not electricity production, but carbon sequestration, and note that BECCS can also be used to reduce emissions in the transportation and industrial sectors. Publishing in the Journal of Geophysical Research: Atmospheres, Garnaud and Sushama (2015) examine the second question. In order to do this they downscale output from a global climate model using a regional climate model that can simulate vegetation dynamics. They find that the projected future increases to growing season length result in greater vegetation productivity and biomass, though this plateaus at the end of of the 21st century. Their projections also indicate an increase in the water-use efficiency of plants, but decreased plant productivity in the southeastern US over the 2071-2100 period. In addition, they find that accounting for vegetation feedbacks leads to increased warming in summer at higher latitudes and a reduction in summer warming at lower latitudes.
PCIC science brief: Possible artifacts of data biases in the recent global surface warming hiatus
(Pacific Climate Impacts Consortium (PCIC), 2015-07) Pacific Climate Impacts Consortium (PCIC)
In a recent paper published in Science, Karl et al. (2015) revise the National Oceanic and Atmospheric Administration's (NOAA) surface temperature data set and examine temperature trends in the updated data. The authors use a sea surface temperature data set that has been corrected for biases in sea surface data that arise due to the difference in measurements from ships and buoys, and the authors incorporate a much larger amount of data from land-based observations. They find that the global warming trend in the updated data set over the 1998-2012 period is just over double of that in the old data set, about 0.086 °C per decade, compared to 0.039 °C per decade. This is largely due to the corrections in sea surface temperature measurements. The updated data shows a statistically significant global warming trend over the 1998-2012 period and the authors note that their results "do not support the notion of a 'slowdown' in the increase of global surface temperature."
PCIC science brief: Projected changes in short-term climate variability induced by human activities
(Pacific Climate Impacts Consortium (PCIC), 2025-08) Pacific Climate Impacts Consortium (PCIC)
Internal climate variability occurs due to interactions between the parts of the Earth’s climate system and is an indelible feature of both observed and model-simulated climate . Anthropogenic climate change may alter the internal variability of the climate system which could, in turn, influence both the mean climate and extremes. Writing in the Journal of Climate, Coquereau and colleagues (2024) used global climate model simulations to examine how internal climate variability might change as the planet warms. In their article titled, “Anthropogenic Changes in Interannual-to-Decadal Climate Variability in CMIP6 Multiensemble Simulations,” the authors noted two regions in particular where changes in climate variability are manifested in future. The first is a decrease in temperature variability at higher latitudes, associated with the retreat of sea ice and the moderation of air temperature by the now exposed ocean surface. The second is an increase in the short-term variability of temperature and precipitation at low latitudes, which appears to reflect an increase in the frequency of the El Niño-Southern Oscillation. This Science Brief discusses these findings and what they might mean for the future climate in British Columbia.
PCIC science brief: Projected changes to grasslands and three US crops
(Pacific Climate Impacts Consortium (PCIC), 2017-05) Pacific Climate Impacts Consortium (PCIC)
Two recently published articles explore how projected changes to climate and carbon dioxide in the atmosphere may affect grasslands in temperate regions and three crops in the United States. Addressing the first question in Nature Climate Change, Obermeier et al. (2017) find that the carbon dioxide fertilization effect in C3 grasslands is reduced when conditions are wetter, dryer or hotter than the conditions to which the grasses are adapted. Publishing in Nature Communications, Schauberger et al. (2017) examine the second question. They find that yields for wheat, soy and corn decline at projected temperatures greater than 30°C, with reductions in yield of 22% for wheat, 40% for soy and 49% for corn. While carbon fertilization does reduce the loss in yields, the effect is much smaller than that of irrigation, suggesting that water stress at higher temperatures may be largely responsible for losses.
PCIC science brief: Projected changes to short-duration extreme rainfall
(Pacific Climate Impacts Consortium (PCIC), 2015-12) Pacific Climate Impacts Consortium (PCIC)
Publishing in the Reviews of Geophysics, Westra et al (2014) summarize the current state of research in the analysis of future changes to the intensity, frequency and duration of extreme rainfall. Their literature review highlights the complicated relationship between short duration extreme rainfall and atmospheric temperature. In some locations, such extreme precipitation does not simply scale with the ability of the atmosphere to hold moisture (i.e. at the Clausius-Clapyron rate of 6 to 7% per C). Instead, at these locations the general pattern is that such a relationship is found to hold up to about 12 C, but between 12 and 24 C extreme precipitation appears to increase more strongly with warming. This is partly due to an increase in convective rainfall. However, above about 24 C, the pattern at these locations is one in which the response of precipitation to increasing temperature appears to be weaker, eventually reversing. This may be due to decreased moisture availability at these temperatures, though Westra et al. note that "the mechanism that causes these moisture deficits remains to be investigated." The authors also find that anticipated changes in sub-daily precipitation associated with a warming climate will "significantly affect the magnitude and frequency of urban and rural flash floods. Compared to daily rainfall, Westra et al. find that sub-daily and sub-hourly rainfall are more sensitive to local surface temperatures. They also report that while sub-daily precipitation observations are too scarce to determine regional trends, geographic location will likely affect rates of change in daily precipitation extremes. In terms of making projections of future changes in these events, the authors find that, owing to the resolution of current global climate models, they are limited in their ability to simulate such precipitation events. In particular, the models are generally not run at sufficient resolution to accurately resolve the necessary convective processes, though some very high-resolution “convection permitting” regional climate models operate at a sufficient resolution to potentially be useful in projecting such extremes. One implication of these findings is that we cannot currently make credible projections of sub-daily rainfall events.
PCIC science brief: Sea level rise observations and acceleration
(Pacific Climate Impacts Consortium (PCIC), 2018-02) Pacific Climate Impacts Consortium (PCIC)
Three recent journal articles examine the rate of sea level rise and the ability of models to accurately simulate sea level rise at a global and regional scale. Publishing in Geophysical Research Letters, Yi et al. (2017) examine the rate at which sea level rise is accelerating and find that the rate of acceleration over the 2005-2015 period is three times faster than it was over the 1993-2014 period and an order of magnitude larger than the acceleration over the 1920-2011 period. They also identify three primary contributors to this acceleration: the thermal expansion of sea water, reduced storage of water on land and the melting of ice on land. In a pair of articles published in the Journal of Climate, Slangen et al. (2017) and Meyssignac et al. (2017) analyze the of climate models to simulate both global and regional sea level rise. They find that simulations can only explain about half (50% ± 30%) of the observed sea level rise. After bias corrections are included for the Greenland ice sheet and the possibility that ice sheets and the deep ocean were not in equilibrium with the 20th Century climate, the models explain about three-quarters (75% ± 38%) of the observed 20th Century sea level rise and all (105% ± 35%) of the observed sea level rise over the period from 1993-1997 to 2011-2015 period. Regionally, climate models underestimate the amount of sea level rise that occured, but do show reasonable agreement for interannual and multidecadal variability. When the same bias corrections are applied, the models come into closer agreement with observations. In addition, they find that the spatial variability in regional sea level rise is largely due to the thermal expansion of sea water and ongoing isostatic adjustment resulting from the end of the last glacial period.
PCIC science brief: Should the RCP 8.5 scenario represent business as usual?
(Pacific Climate Impacts Consortium (PCIC), 2021-06) Pacific Climate Impacts Consortium (PCIC)
The state of the future climate depends on human actions, primarily the emission of greenhouse gases and other industrial pollutants. This raises the questions: "What path are recent historical emissions following?" "What path would we be on, if we continue with business-as-usual, in the absence of further mitigation action?" And, "Are these paths reliable guides to future emissions?" One scenario that is commonly used in the scientific literature, RCP 8.5, is often referred to as "business-as-usual." Recently, some scientists have taken issue with this description, saying it is unrealistic and may hinder the goal of emissions reductions policy. Others argue that, in fact, RCP 8.5 is the scenario that most closely tracks cumulative emissions to date, that it is thus of the most use for planning out to the middle of the century. In this Science Brief, we unpack each of these arguments and evaluate what these differing perspectives can tell us about the ultimate objective of emissions scenarios as tools for exploring future climate change.
PCIC science brief: Storm surges and projected changes to atmospheric river events in coastal BC
(Pacific Climate Impacts Consortium (PCIC), 2016-09) Pacific Climate Impacts Consortium (PCIC)
Two articles recently published in the peer reviewed literature examine two types of extreme weather events that affect coastal British Columbia, storm surge events and atmospheric river events. The first paper, by Soontiens et al. (2016) in Atmosphere-Ocean examines the ability of a numerical ocean model to simulate storm surges in the Strait of Georgia and the relative contribution of several factors to storm surge amplitude in the region. The authors use the model to simulate six storm surge events from the 2006-2012 period at four locations and find that the model does well at reproducing the magnitude of storm surges. They also find that the primary contribution to storm surges in the region are sea surface height anomalies from the Pacific, with local wind patterns causing small spatial differences in the sea surface height. The second paper, by Hagos et al. (2016) in Geophysical Research Letters uses output from a global climate model to examine changes to atmospheric river events over western North America, assuming large, business-as-usual anthropogenic greenhouse gas emissions. The authors' projections show an increase of about 35% in days on which atmospheric rivers make landfall in the last 20 years of the 21st century when compared to the last 20 years of the 20th century. Their projections also show a resulting increase of about 28% in extreme precipitation days.
PCIC science brief: The accelerated loss of Western Canadian glaciers
(Pacific Climate Impacts Consortium (PCIC), 2022-04) Pacific Climate Impacts Consortium (PCIC)
As a consequence of global warming, the world's glaciers have been shrinking. Changes to glaciers in BC could have wide-ranging impacts to BC's ecosystems and human communities, across multiple sectors. Remote sensing data has been invaluable in measuring and characterizing changes to the world's glaciers. Recent research published in Remote Sensing of the Environment using such data shows that western Canadian glaciers have been melting at an accelerating rate and examines how this is related to changes in seasonal temperature and precipitation. Here we discuss what these results tell us about changes to western Canada's glaciers.
PCIC science brief: The evolution of snowmelt and drought
(Pacific Climate Impacts Consortium (PCIC), 2017-10) Pacific Climate Impacts Consortium (PCIC)
Two articles recently published in the peer reviewed literature examine how the rate of snowmelt may change as the Earth's climate changes, and how droughts can evolve and move over time. Publishing in Nature Climate Change, Musselman et al. (2017) examine the effect that global warming may have on snowmelt. They find that the portion of snow melt occurring at moderate and high melt rates in Western North America is projected to decrease, while the portion occurring at low melt rates is projected to increase. Total meltwater volume is projected to decrease. In recent research published in Geophysical Research Letters, Herrera-Estrada et al. (2017) explore how droughts evolve in space and time across six continents. They find that clusters of droughts can travel hundreds to thousands of kilometers across each continent. In addition, the authors find that longer-lasting droughts tend to travel farther, as well as be more severe.
PCIC science brief: The human climate niche, past, present and future
(Pacific Climate Impacts Consortium (PCIC), 2022-01) Pacific Climate Impacts Consortium (PCIC)
This Science Brief covers a paper in the Proceedings of the National Academy of Sciences, by Xu et al. (2020), who use global climate model (GCM) output, weather station data, estimates of historical global population density, and data on global gross domestic product (GDP), crop and livestock production, to determine if there has been a human climate niche. They determine that such a niche has existed. For the past 6000 years, human populations have lived largely in a fairly narrow range of climates and populations clustered around two temperature ranges, with most people living in a range of about 11 C to about 15 °C for mean annual temperature and a smaller, but significant portion living in a range around 20 °C to about 25 °C. They then examine how this niche may change in the future. They find that, under a high emissions scenario, this niche is projected to shift spatially more in the upcoming 50 years than it has in the past 6000, leaving a third of the projected future human population in regions where the mean annual temperature is greater than 29 °C.