The effectiveness of climate clubs under Donald Trump

On 1 June 2017, President Trump announced that the US intends to leave the Paris Agreement if no alternative terms acceptable to his administration can be agreed upon. In this article, an agent-based model of bottom-up climate mitigation clubs is used to derive the impact that lack of US participation may have on the membership of such clubs and their emissions coverage. We systematically analyse the prospects for climate mitigation clubs, depending on which of three conceivable roles the US takes on: as a leader (for benchmarking), as a follower (i.e. willing to join climate mitigation clubs initiated by others if this is in its best interest) or as an outsider (i.e. staying outside of any climate mitigation club no matter what). We investigate these prospects for three types of incentives for becoming a member: club goods, conditional commitments and side-payments. Our results show that lack of US leadership significantly constrains climate clubs’ potential. Lack of US willingness to follow others’ lead is an additional, but smaller constraint. Only in a few cases will US withdrawal entail widespread departures by other countries. We conclude that climate mitigation clubs can function without the participation of an important GHG emitter, given that other major emitters show leadership, although these clubs will rarely cover more than 50% of global emissions.

Key policy insights

• The US switching from being a leader to being a follower substantially reduces the emissions coverage of climate mitigation clubs.

• The US switching from being a follower to being an outsider sometimes reduces coverage further, but has a smaller impact than the switch from leader to follower.

• The switch from follower to outsider only occasionally results in widespread departures by other countries; in a few instances it even entices others to join.

• Climate mitigation clubs can function even without the participation of the US, provided that other major emitters show leadership; however, such clubs will typically be unable to cover more than 50% of global emissions.

• Climate mitigation clubs may complement the Paris Agreement and can also serve as an alternative in case Paris fails.

     

MODIS-NDVI-based mapping of the length of the growing season in northern Fennoscandia

Northern Fennoscandia is an ecologically heterogeneous region in the arctic/alpine-boreal transition area. Phenology data on birch from 13 stations and 16-day MODIS-NDVI composite satellite data with 250 m resolution for the period 2000 to 2006 were used to map the growing season. A new combined pixel-specific NDVI threshold and decision rule-based mapping method was developed to determine the onset and end of the growing season. A moderately high correlation was found between NDVI data and birch phenology data. The earliest onset of the growing season is found in the narrow strip of lowland between the mountains and the sea along the coast of northern Norway. The onset follows a clear gradient from lowland to mountain corresponding to the decreasing temperature gradient. In autumn, the yellowing of the vegetation shows a more heterogeneous pattern. The length of the growing season is between 100 and 130 days in 55% of the study area.     

Rare earth elements in some igneous rocks in the Oslo rift, Norway

Rare earth element (REE) concentrations have been determined for 27 plutonic rocks in the Permian Oslo rift, including kjelsåsite/larvikites, lardalites, nordmarkites, ekerites and Drammen granites.

The kjelsåsite/larvikites from different parts of the rift have very similar REE concentrations and must be derived from a source or sources homogeneous with respect to REE.

The genetic relations between the kjelsåsite/larvikites and the other rocks were tested by comparing observed REE enrichment factors with calculated ones based on hypothetical fractionation relations derived from petrographic mixing calculations. Several of the analyzed nordmarkites may be derived from kjelsåsitic/larvikitic parent magmas: the ekerites are closely related to the nordmarkites.     

U–Pb TIMS age constraints on the evolution of the Neoproterozoic Meatiq Gneiss Dome,Eastern Desert,Egypt

Ages are used to constrain the temporal evolution of the Meatiq Gneiss Dome, Eastern Desert, Egypt, by dating (ID-TIMS) pre-, syn-, and post-tectonic igneous rocks in and around the dome. The Um Ba’anib Orthogneiss, comprising the deepest exposed structural levels of the dome, has a crystallization age of 630.8 ± 2 Ma. The overlying mylonites are interpreted to be a thrust sheet/complex (Abu Fannani Thrust Sheet) of highly mylonitized metasediments (?), migmatitic amphibolites, and orthogneisses with large and small tectonic lenses of less-deformed intrusives. Two syn-tectonic diorite lenses in this complex have crystallization ages of 609.0 ± 1.0 and 605.8 ± 0.9 Ma, respectively. The syn-tectonic Abu Ziran diorite, cutting across the tectonic contact between mylonite gneisses of the Abu Fannani Thrust Sheet and a structurally overlying thrust sheet of eugeoclinal rocks (“Pan-African nappe”), has a magmatic emplacement age of 606.4 ± 1.0 Ma. Zircons from a gabbro (Fawakhir ophiolite) within the eugeoclinal thrust sheet yielded a crystallization age of 736.5 ± 1.2 Ma. The post-tectonic Fawakhir monzodiorite intrudes the ophiolitic rocks and has an emplacement age of 597.8 ± 2.9 Ma. Two other post-tectonic granites, the Arieki granite that intrudes the foliated Um Ba’anib Orthogneiss, and the Um Had granite that cuts the deformed Hammamat sediments, have emplacement ages of 590 ± 3.1 and 596.3 ± 1.7 Ma, respectively. We consider formation of the Meatiq Gneiss Dome to be a young structural feature (<631 Ma), and our preferred tectonic interpretation is that it formed as a result of NE–SW shortening contemporaneous with folding of the nearby Hammamat sediments around 605–600 Ma, during oblique collision of East and West Gondwana.     

Joint AVO inversion, wavelet estimation and noise-level estimation using a spatially coupled hierarchical Bayesian model

The main objective of the AVO inversion is to obtain posterior distributions for P-wave velocity, S-wave velocity and density from specified prior distributions, seismic data and well-log data. The inversion problem also involves estimation of a seismic wavelet and the seismic-noise level. The noise model is represented by a zero mean Gaussian distribution specified by a covariance matrix. A method for joint AVO inversion, wavelet estimation and estimation of the noise level is developed in a Bayesian framework. The stochastic model includes uncertainty of both the elastic parameters, the wavelet, and the seismic and well-log data. The posterior distribution is explored by Markov-chain Monte-Carlo simulation using the Gibbs' sampler algorithm. The inversion algorithm has been tested on a seismic line from the Heidrun Field with two wells located on the line. The use of a coloured seismic-noise model resulted in about 10% lower uncertainties for the P-wave velocity, S-wave velocity and density compared with a white-noise model. The uncertainty of the estimated wavelet is low. In the Heidrun example, the effect of including uncertainty of the wavelet and the noise level was marginal with respect to the AVO inversion results.     

Geologic constraints on middle-crustal behavior during broadly synorogenic extension in the central East Greenland Caledonides

Structural and U-Pb geochronologic data from the Forsblad Fjord area of East Greenland (72°30'N) indicate close spatial and temporal ties between orogen-parallel shear and extensional deformation during Caledonian orogenesis. This territory is composed of three tectonostratigraphic units separated by two splays of the Fjord Region Detachment System (FRDS), a principal extensional fault system of the East Greenland Caledonides that was active in Silurian time. The oldest Caledonian fabrics in Forsblad Fjord, which developed at upper amphibolite facies metamorphic conditions, indicate that there was north-south, lateral extrusion of ductile middle-crustal material synchronous with approximately east-west shortening. U-Pb dating of synkinematic granitic leucosomes in migmatitic schists and gneisses demonstrates that this process was underway at ca. 425 Ma. Subsequently, east-west extension along the two splays of the FRDS truncated the older fabrics; the structurally highest of these shear zones - the Tindern detachment - was active as early as ca. 424 Ma. This implies either that there was a rapid transition from Caledonian shortening and possible transpressional deformation to post-orogenic collapse, or our preferred interpretation that extension was synorogenic. The FRDS shares many structural characteristics with the South Tibetan Detachment System of the Cenozoic Himalayan orogen but exhibits two important differences. First, while the South Tibetan system developed in the down-going Indian plate during the India-Eurasia collision, the Fjord Region system developed in the overriding Laurentian plate during the collision of Laurentia with Baltica. Second, whereas the exposed extensional structures in the Himalayas developed in the upper crust and are only inferred to have extended to deeper levels, those in the Forsblad Fjord area were demonstrably active at middle-crustal levels. Evidence for broadly coeval extension and contraction at differen t structural levels in both mountain belts emphasizes the general importance of crustal decoupling in the collisional orogenic process, and implies that synorogenic extensional deformation is not strictly an upper crustal phenomenon.     

Neoproterozoic basin evolution in Fennoscandia, East Greenland and Svalbard

Neoproterozoic successions of Fennoscandia, East Greenland and Svalbard are related to crustal extension and formation of sedimentary basins along the margins of northern Baltica （ Fennoscandia ） and eastern Laurentia （East Greenland and Svalbard）, preceding final break-up of Rodinia. The early rift stage （late Tonian-Cryogenian） is characterized by up to 16 km thick sedimentary successions of deep-marine sandstones and conglomerates linked to rift and strike-slip basins. Pericratonic basins expanded during Cryogenian-Cambrian coastal onlap. Cryogenian tropical climate is reflected by carbonate and evaporitic formations, most of which predate Cryogenian-Ediacaran glaciations. Glacial units, collectively referred to the Varanger Ice Age, may be equivalent to the Marinoan （c. 630 Ma） and the Gaskiers （c. 580 Ma） glacial periods. The final stage in break-up of Rodinia commenced with the emplacement of dolerite dyke swarms along the Baltoscandian margin at c. 600 Ma and the opening of the lapetus Ocean and other sea ways. No such dyke swarms have been recorded along the East Greenland segment of the Laurentian margin. Several Tonian-Cambrian tectonic and magmatic events recorded within the Kalak Nappe Complex in northern Finnmark make this unit an exotic terrane relative to the autochthonous Baltoscandian platform.