Climate policy implications of nonlinear decline of Arctic land permafrost and other cryosphere elements

Arctic feedbacks accelerate climate change through carbon releases from thawing permafrost and higher solar absorption from reductions in the surface albedo, following loss of sea ice and land snow. Here, we include dynamic emulators of complex physical models in the integrated assessment model PAGE-ICE to explore nonlinear transitions in the Arctic feedbacks and their subsequent impacts on the global climate and economy under the Paris Agreement scenarios. The permafrost feedback is increasingly positive in warmer climates, while the albedo feedback weakens as the ice and snow melt. Combined, these two factors lead to significant increases in the mean discounted economic effect of climate change: +4.0% ($24.8 trillion) under the 1.5 °C scenario, +5.5$33.8 trillion) under the 2 °C scenario, and +4.8% ($66.9 trillion) under mitigation levels consistent with the current national pledges. Considering the nonlinear Arctic feedbacks makes the 1.5 °C target marginally more economically attractive than the 2 °C target, although both are statistically equivalent.This work is part of the ICE-ARC project funded by the European Union’s 7th Framework Programme, (grant 603887, contribution 006). D.Y. received additional funding from ERIM, Erasmus University Rotterdam, and Paul Ekins at the ISR, University College London. K.S. was funded by NSF (grant 1503559) and NASA (grants NNX14A154G, NNX17AC59A). E.J. was funded by the NGEE Arctic project supported by the BER Office of Science at the U.S. DOE. Y.E. was funded by the NSF (grant 1900795). E.B. was supported by the UK Met Office Hadley Centre Climate Programme funded by BEIS and DEFRA

Can convective precipitation variability be deduced from the variability in CAPE and CIN? An analysis of global CAPE and CIN variability in present and future climates

The variability of convective precipitation is relevant for its prediction on short and long time scales. On short time scales severe weather events are vital for weather forecasting, on long time scales convection anomalies affect wetness and droughts. Since convective precipitation requires parameterisation in numerical models, CAPE (convective available potential energy) and CIN (convective inhibition) are applied to estimate trends and long-term memory. Their variability is determined in present-day climate (ECMWF reanalysis: 6 hourly during 1979-2001 in T106 trun- cation; ECHAM5/MPI-OM, 20C simulation: 6 hourly during 1902-2001 in T63 truncation) and a possible warmer future scenario (ECHAM5/MPI-OM, A1B scenario: 6 hourly during 2002-2101 in T63 truncation). Future changes in CAPE and CIN reveal similar changes for small, mean and large values. A global pattern is found of increasing values in CAPE and CIN over most regions of the conti- nents and northern hemispheric ocean basins, while decreasing values are found over the Southern Ocean. This pattern changes towards mostly positive trends if CAPE is analysed for large CIN occurring simultaneously. In contrast, the original pattern remains similar if CAPE is investigated for small CIN. Temperature and humidity, which form the basis of CAPE and CIN, show almost entirely higher values in the future. Decreasing values in CAPE and CIN correlate with large scale patterns like the North Atlantic Oscillation (NAO), El Ni ̃ no/Southern Oscillation (ENSO) and the Southern Annular Mode (SAM). Furthermore, a southward shift of the descending branch of the southern hemisphere Hadley Cell in a warmer climate decreases CAPE further. The correlations of CAPE with the above named teleconnections influence the distribution of global memory on long time scales. The influence of ENSO on the memory in CAPE and CIN intensifies in a warmer climate with regards to spread and frequency. Furthermore, the impact of the NAO on CAPE also spreads in terms of location, while the frequency remains similar in a warmer climate. In contrast, the regions where SAM influences CAPE decrease due to declining values of the SAM index. Additional analyses with an ECHAM5 simulation and climatological sea surface temperature reveal that the variability of the ocean has a stronger influence on CAPE than on CIN

Random data for testing purposes

These data are purely random and have been created to test scripts with

Transarktische Seerouten

Schiffahrtsrouten zwischen Atlantik und Pazifik.Der Rückgang des Meereisesöffnet denArktischen Ozean für wirtschaftliche Aktivitäten, die bisher wegen der schwere Zugänglichkeitdieses Meeresgebiets undenkbar waren über die FRamstraße und die Bering-straße verbindet das Nordpolarmeer Atlantik und Pazifikund erlaubt wegen der deutlichkürzeren Strecke als durch Suez-und Pabamakanaleine wirtschaftlich günstigeAlternativefür den Handel zwischenden Produzenten und Abnehmernan beiden großen Ozeanen.Neben derwachsenden Rohstoffausbeute erwartet man daher zukünftig einen zunehmenden transpolaren Schiffsverkehr. Die transpolaren Routenbieten sich als Ausweichsrtreckena, wenn der Schifffahrtswegdurchden Isthmus von Panamawegen technischer Probleme oder Wege jenseits des Suezkanals wegen Piraterie ausfallen sollten

Global climatology of Convective Available Potential Energy (CAPE) and Convective Inhibition (CIN) in ERA-40 reanalysis

Convective Available Potential Energy (CAPE) and Convective Inhibition (CIN) play a dominant role in convective precipitation, its genesis and intensity. A global climatology of CAPE and CIN is presented in terms of seasonal means, variances, and trends based on 44 years (1958–2001) of six-hourly ERA-40 reanalysis (European Centre for Medium-Range Weather Forecast ECMWF, T106 resolution). CAPE shows large values and high variability in the tropics with maxima over the continents; the seasonal changes are dominated by specific humidity. CIN shows large means and variability in the subtropics. Significant trends in CAPE and CIN give the following results: (i) In general, a CAPE increase is noted during all seasons while, in particular, in autumn CIN shows a decrease over continents. (ii) Splitting of the time series reveals a sign change in trend commencing at the end of the 70s; this is observed in parts of the tropical continents and North America. CAPE and CIN show trends of opposite sign with CAPE increasing in the first half and a decrease during the second half (and vice versa for CIN)

GPS data of drifting buoy 2018T55 deployed in the Pacific sector of the Arctic Ocean during the TRANSDRIFT/TICE/NABOS expedition in summer 2018

The buoy was, among others, installed on sea ice floes during the TRANSDRIFT/TICE/NABOS expedition onboard the Akademik Tryoshnikov in Aug/Sep 2018. The buoy subsequently drifted through the Transpolar Drift of the Arctic Ocean for several months, documenting the drift of the pack ice, until they ceased transmitting. The SIMBA measured GPS time, latitude and longitude and transmitted those data via the iridium satellite network at 2-hourly intervals