scholarly journals Simulated long-term climate response to idealized solar geoengineering

2016 ◽  
Vol 43 (5) ◽  
pp. 2209-2217 ◽  
Author(s):  
Long Cao ◽  
Lei Duan ◽  
Govindasamy Bala ◽  
Ken Caldeira
Keyword(s):  
Climate Response ◽  
Solar Geoengineering

Long-term climate response to stabilized and overshoot anthropogenic forcings beyond the twenty-first century

2006 ◽  
Vol 28 (2-3) ◽  
pp. 199-214 ◽  
Author(s):  
Junichi Tsutsui ◽  
Yoshikatsu Yoshida ◽  
Dong-Hoon Kim ◽  
Hideyuki Kitabata ◽  
Keiichi Nishizawa ◽  
...  
Keyword(s):  
First Century ◽  
Climate Response ◽  
Twenty First Century ◽  
Anthropogenic Forcings

scholarly journals Chaotic climate response to long-term solar forcing variability

2009 ◽  
Vol 88 (6) ◽  
pp. 60004 ◽  
Author(s):  
A. Bershadskii
Keyword(s):  
Climate Response ◽  
Solar Forcing

scholarly journals OPTIMAL CLIMATE POLICY IN 3D: MITIGATION, CARBON REMOVAL, AND SOLAR GEOENGINEERING

2021 ◽  
pp. 2150008
Author(s):  
MARIIA BELAIA ◽  
JUAN B. MORENO-CRUZ ◽  
DAVID W. KEITH
Keyword(s):  
Climate Model ◽  
Integrated Assessment Model ◽  
Assessment Model ◽  
Short Term ◽  
Trade Offs ◽  
Solar Geoengineering ◽  
Optimal Climate Policy ◽  
The Cost ◽  
Far Future

We introduce solar geoengineering (SG) and carbon dioxide removal (CDR) into an integrated assessment model to analyze the trade-offs between mitigation, SG, and CDR. We propose a novel empirical parameterization of SG that disentangles its efficacy, calibrated with climate model results, from its direct impacts. We use a simple parameterization of CDR that decouples it from the scale of baseline emissions. We find that (a) SG optimally delays mitigation and lowers the use of CDR, which is distinct from moral hazard; (b) SG is deployed prior to CDR while CDR drives the phasing out of SG in the far future; (c) SG deployment in the short term is relatively independent of discounting and of the long-term trade-off between SG and CDR over time; (d) small amounts of SG sharply reduce the cost of meeting a [Formula: see text]C target and the costs of climate change, even with a conservative calibration for the efficacy of SG.

scholarly journals Experiments based on blue intensity for reconstructing North Pacific temperatures along the Gulf of Alaska

2017 ◽  
Vol 13 (8) ◽  
pp. 1007-1022 ◽  
Author(s):  
Rob Wilson ◽  
Rosanne D'Arrigo ◽  
Laia Andreu-Hayles ◽  
Rose Oelkers ◽  
Greg Wiles ◽  
...  
Keyword(s):  
Tree Ring ◽  
North Pacific ◽  
Ring Width ◽  
Gulf Of Alaska ◽  
Climate Response ◽  
Cool Period ◽  
Climate Signal ◽  
Latewood Density ◽  
Blue Intensity

Abstract. Ring-width (RW) records from the Gulf of Alaska (GOA) have yielded a valuable long-term perspective for North Pacific changes on decadal to longer timescales in prior studies but contain a broad winter to late summer seasonal climate response. Similar to the highly climate-sensitive maximum latewood density (MXD) proxy, the blue intensity (BI) parameter has recently been shown to correlate well with year-to-year warm-season temperatures for a number of sites at northern latitudes. Since BI records are much less labour intensive and expensive to generate than MXD, such data hold great potential value for future tree-ring studies in the GOA and other regions in mid- to high latitudes. Here we explore the potential for improving tree-ring-based reconstructions using combinations of RW- and BI-related parameters (latewood BI and delta BI) from an experimental subset of samples at eight mountain hemlock (Tsuga mertensiana) sites along the GOA. This is the first study for the hemlock genus using BI data. We find that using either inverted latewood BI (LWBinv) or delta BI (DB) can improve the amount of explained temperature variance by > 10 % compared to RW alone, although the optimal target season shrinks to June–September, which may have implications for studying ocean–atmosphere variability in the region. One challenge in building these BI records is that resin extraction did not remove colour differences between the heartwood and sapwood; thus, long term trend biases, expressed as relatively warm temperatures in the 18th century, were noted when using the LWBinv data. Using DB appeared to overcome these trend biases, resulting in a reconstruction expressing 18th–19th century temperatures ca. 0.5 °C cooler than the 20th–21st centuries. This cool period agrees well with previous dendroclimatic studies and the glacial advance record in the region. Continuing BI measurement in the GOA region must focus on sampling and measuring more trees per site (> 20) and compiling more sites to overcome site-specific factors affecting climate response and using subfossil material to extend the record. Although LWBinv captures the inter-annual climate signal more strongly than DB, DB appears to better capture long-term secular trends that agree with other proxy archives in the region. Great care is needed, however, when implementing different detrending options and more experimentation is necessary to assess the utility of DB for different conifer species around the Northern Hemisphere.

scholarly journals North Atlantic Climate Response to Lake Agassiz Drainage at Coarse and Ocean Eddy-Permitting Resolutions

2013 ◽  
Vol 26 (8) ◽  
pp. 2651-2667 ◽  
Author(s):  
Paul Spence ◽  
Oleg A. Saenko ◽  
Willem Sijp ◽  
Matthew H. England
Keyword(s):  
North Atlantic ◽  
Meridional Overturning Circulation ◽  
Climate Response ◽  
Model Resolution ◽  
Lake Agassiz ◽  
The North ◽  
Freshwater Forcing ◽  
North Atlantic Climate ◽  
The North Atlantic

Abstract The North Atlantic climate response to the catastrophic drainage of proglacial Lake Agassiz into the Labrador Sea is analyzed with coarse and ocean eddy-permitting versions of a global coupled climate model. The North Atlantic climate response is qualitatively consistent in that a large-scale cooling is simulated regardless of the model resolution or region of freshwater discharge. However, the magnitude and duration of the North Atlantic climate response is found to be sensitive to model resolution and the location of freshwater forcing. In particular, the long-term entrainment of freshwater along the boundary at higher resolution and its gradual, partially eddy-driven escape into the interior leads to low-salinity anomalies persisting in the subpolar Atlantic for decades longer. As a result, the maximum decline of the Atlantic meridional overturning circulation (AMOC) and the ocean meridional heat transport (MHT) is amplified by about a factor of 2 at ocean eddy-permitting resolution, and the recovery is delayed relative to the coarse grid model. This, in turn, increases the long-term cooling in the high-resolution simulations. A decomposition of the MHT response reveals an increased role for transients and the horizontal mean component of MHT at higher resolution. With fixed wind stress curl, it is a stronger response of bottom pressure torque to the freshwater forcing at higher resolution that leads to a larger anomaly of the depth-integrated circulation.

scholarly journals Using Single-Forcing GCM Simulations to Reconstruct and Interpret Quaternary Climate Change

2015 ◽  
Vol 28 (24) ◽  
pp. 9746-9767 ◽  
Author(s):  
Michael P. Erb ◽  
Charles S. Jackson ◽  
Anthony J. Broccoli
Keyword(s):  
Climate Change ◽  
Greenhouse Gases ◽  
Ice Sheets ◽  
Meridional Overturning Circulation ◽  
Climate Response ◽  
Climate Variations ◽  
Past Climate ◽  
Quaternary Climate ◽  
Temperature Records

Abstract The long-term climate variations of the Quaternary were primarily influenced by concurrent changes in Earth’s orbit, greenhouse gases, and ice sheets. However, because climate changes over the coming century will largely be driven by changes in greenhouse gases alone, it is important to better understand the separate contributions of each of these forcings in the past. To investigate this, idealized equilibrium simulations are conducted in which the climate is driven by separate changes in obliquity, precession, CO2, and ice sheets. To test the linearity of past climate change, anomalies from these single-forcing experiments are scaled and summed to compute linear reconstructions of past climate, which are then compared to mid-Holocene and last glacial maximum (LGM) snapshot simulations, where all forcings are applied together, as well as proxy climate records. This comparison shows that much of the climate response may be approximated as a linear response to forcings, while some features, such as modeled changes in sea ice and Atlantic meridional overturning circulation (AMOC), appear to be heavily influenced by nonlinearities. In regions where the linear reconstructions replicate the full-forcing experiments well, this analysis can help identify how each forcing contributes to the climate response. Monsoons at the mid-Holocene respond strongly to precession, while LGM monsoons are heavily influenced by the altered greenhouse gases and ice sheets. Contrary to previous studies, ice sheets produce pronounced tropical cooling at the LGM. Compared to proxy temperature records, the linear reconstructions replicate long-term changes well and also show which climate variations are not easily explained as direct responses to long-term forcings.

scholarly journals Experimental reaction rates constrain estimates of ozone response to calcium carbonate geoengineering

2020 ◽  
Vol 1 (1) ◽  
Author(s):  
Zhen Dai ◽  
Debra K. Weisenstein ◽  
Frank N. Keutsch ◽  
David W. Keith
Keyword(s):  
Ozone Depletion ◽  
Reaction Rates ◽  
Reaction Model ◽  
Systematic Uncertainties ◽  
Solar Geoengineering ◽  
Uptake Coefficients ◽  
Ozone Column ◽  
Global Mean

AbstractStratospheric solar geoengineering (SG) would impact ozone by heterogeneous chemistry. Evaluating these risks and methods to reduce them will require both laboratory and modeling work. Prior model-only work showed that CaCO3 particles would reduce, or even reverse ozone depletion. We reduce uncertainties in ozone response to CaCO3 via experimental determination of uptake coefficients and model evaluation. Specifically, we measure uptake coefficients of HCl and HNO3 on CaCO3 as well as HNO3 and ClONO2 on CaCl2 at stratospheric temperatures using a flow tube setup and a flask experiment that determines cumulative long-term uptake of HCl on CaCO3. We find that particle ageing causes significant decreases in uptake coefficients on CaCO3. We model ozone response incorporating the experimental uptake coefficients in the AER-2D model. With our new empirical reaction model, the global mean ozone column is reduced by up to 3%, whereas the previous work predicted up to 27% increase for the same SG scenario. This result is robust under our experimental uncertainty and many other assumptions. We outline systematic uncertainties that remain and provide three examples of experiments that might further reduce uncertainties of CaCO3 SG. Finally, we highlight the importance of the link between experiments and models in studies of SG.

scholarly journals Regional climate of the Larsen B embayment 1980–2014

2017 ◽  
Vol 63 (240) ◽  
pp. 683-690 ◽  
Author(s):  
A. A. LEESON ◽  
J. M. VAN WESSEM ◽  
S. R. M. LIGTENBERG ◽  
A. SHEPHERD ◽  
M. R. VAN DEN BROEKE ◽  
...  
Keyword(s):  
Climate Models ◽  
Climate Model ◽  
Regional Climate ◽  
Local Scale ◽  
Climate Response ◽  
Weather Station ◽  
Automatic Weather Station ◽  
Ice Shelf ◽  
The Antarctic

ABSTRACTUnderstanding the climate response of the Antarctic Peninsula ice sheet is vital for accurate predictions of sea-level rise. However, since climate models are typically too coarse to capture spatial variability in local scale meteorological processes, our ability to study specific sectors has been limited by the local fidelity of such models and the (often sparse) availability of observations. We show that a high-resolution (5.5 km × 5.5 km) version of a regional climate model (RACMO2.3) can reproduce observed interannual variability in the Larsen B embayment sufficiently to enable its use in investigating long-term changes in this sector. Using the model, together with automatic weather station data, we confirm previous findings that the year of the Larsen B ice shelf collapse (2001/02) was a strong melt year, but discover that total annual melt production was in fact ~30% lower than 2 years prior. While the year before collapse exhibited the lowest melting and highest snowfall during 1980–2014, the ice shelf was likely pre-conditioned for collapse by a series of strong melt years in the 1990s. Melt energy has since returned to pre-1990s levels, which likely explains the lack of further significant collapse in the region (e.g. of SCAR Inlet).

scholarly journals Responding to the Call for Climate Action

2020 ◽  
Vol 50 (2) ◽  
pp. 237
Author(s):  
Daniel E. Lane
Keyword(s):  
Climate Change ◽  
Adaptive Capacity ◽  
Local Community ◽  
Climate Change Impacts ◽  
Institutional Arrangements ◽  
Climate Response ◽  
Climate Information ◽  
Carbon Footprints ◽  
Climate Action

Global calls for action on climate change have become more urgent in recent years. However, how to act to achieve climate sustainability remains elusive. The evidence is clear that governmental initiatives – global, national, and provincial – have not been able to coalesce into a meaningful strategy for climate sustainability. What is required is a shift in climate responsibility from governments to individuals and communities who think globally but are best able to act locally. To encourage the citizenry to act requires a science-based information and education whereby climate action is clearly defined along with the consequences of actions (or inaction). Education must include a climate curriculum as a mainstream subject in our schools. Using this approach, local community baselines of climate information, vulnerability, and adaptive capacity can be established. In enhancing their climate roles, governments’ need to shift from carrying out mandates for climate response, to becoming auditors of carbon use in which citizens and businesses are given incentives to reduce carbon footprints. Finally, increased investments need to be directed to communities so that they can take more responsibility and be more prepared to live with climate change impacts. Governments also need to engage the community in participatory strategic long-term planning for adaptation to the changing climate. Keywords: climate action, climate responsibility, institutional arrangements, science-based information, education legacy, strategic planning, community investment

Sign in / Sign up

Export Citation Format

Share Document