The nexus between nationally determined contributions and technology needs assessments: a global analysis

The role of technology in combatting climate change through mitigation and adaptation to its inevitable impacts has been acknowledged and highlighted by the Parties to the United Nations Framework Convention on Climate Change (UNFCCC). In the developing world, this has received particular attention through the technology needs assessment (TNA) process. As Parties put forward their national pledges to combat climate change, the scarcity of resources makes it important to assess (i) whether national processes designed to tackle climate change are working together and (ii) whether existing national processes should be terminated with the initiation of new ones. This study presents an assessment of the existing TNA process and its linkages to the nationally determined contributions (NDCs) under the Paris Agreement. The conclusions stem from an assessment of the TNAs completed to date, as well as 71 NDCs from developing countries at various stages of the TNA process. The analyses show that further developing the TNAs could play a vital role in filling gaps in the existing NDCs, specifically those relating to identifying appropriate technologies, their required enabling framework conditions and preparing implementation plans for their transfer and diffusion.

Key policy insights

• The full potential of the TNAs has still to be rolled out in many countries.

• Developing countries can maximize the potential of their TNAs by further developing them to explicitly analyse what is needed to implement existing NDCs, including by better aligning their focus, scope and up-to-dateness with the priority sectors included in the NDCs.

• Requests of developing countries for international assistance, through technology transfer, will be better guided by the completion of the TNA process.

• Policies for strengthening the NDCs will benefit from the results of completed, ongoing and future TNA processes.

     

Sphene and zircon in the Highland Range volcanic sequence (Miocene, southern Nevada, USA): elemental partitioning, phase relations, and influence on evolution of silicic magma

Sphene is prominent in Miocene plutonic rocks ranging from diorite to granite in southern Nevada, USA, but it is restricted to rhyolites in coeval volcanic sequences. In the Highland Range volcanic sequence, sphene appears as a phenocryst only in the most evolved rocks (72?C77 mass% SiO₂; matrix glass 77?C78 mass% SiO₂). Zr-in-sphene temperatures of crystallization are mostly restricted to 715 and 755°C, in contrast to zircon (710?C920°C, Ti-in-zircon thermometry). Sphene rim/glass Kds for rare earth elements are extremely high (La 120, Sm 1200, Gd 1300, Lu 240). Rare earth elements, especially the middle REE (MREE), decrease from centers to rims of sphene phenocrysts along with Zr, demonstrating the effect of progressive sphene fractionation. Whole rocks and glasses have MREE-depleted, U-shaped REE patterns as a consequence of sphene fractionation. Within the co-genetic, sphene-rich Searchlight pluton, only evolved leucogranites show comparable MREE depletion. These results indicate that sphene saturation in intruded and extruded magmas occurred only in highly evolved melts: abundant sphene in less silicic plutonic rocks represents a late-stage ??bloom?? in fractionated interstitial melt.     

A review of observed and projected changes in climate for the islands in the Caribbean

Observed and projected changes in climate have serious socio-economic implications for the Caribbean islands. This article attempts to present basic climate change information—based on previous studies, available observations and climate model simulations—at spatial scales relevant for islands in the Caribbean. We use the General Circulation Model (GCM) data included in the Coupled Model Intercomparison Project phase 3 (CMIP3) and the UK Hadley Centre regional climate model (RCM) data to provide both present-day and scenario-based future information on precipitation and temperature for individual island states. Gridded station observations and satellite data are used to study 20th century climate and to assess the performance of climate models. With main focus on precipitation, we also discuss factors such as sea surface temperature, sea level pressure and winds that affect seasonal variations in precipitation. The CMIP3 ensemble mean and the RCM successfully capture the large-scale atmospheric circulation features in the region, but show difficulty in capturing the characteristic bimodal seasonal cycle of precipitation. Future drying during the wet season in this region under climate change scenarios has been noted in previous studies, but the magnitude of change is highly uncertain in both GCM and RCM simulations. The projected decrease is more prominent in the early wet season erasing the mid-summer drought feature in the western Caribbean. The RCM simulations show improvements over the GCM mainly due to better representation of landmass, but its performance is critically dependent on the driving GCM. This study highlights the need for high-resolution observations and ensemble of climate model simulations to fully understand climate change and its impacts on small islands in the Caribbean.     

Ancient magnetic field determinations on selected chondritic meteorites

Paleofield intensity determinations involving a comparison of the stable natural remanence (NRM) component with a laboratory thermoremanence (TRM) were carried out on nine chondrites selected in Brecher and Fuhrman (1979a, this issue, hereafter called Paper I), as well as on two manifestly unsuitable controls. To judge their reliability: (1) heat-alteration was monitored by comparing saturation coercivity spectra before and after heating; and (2) the NRM and TRM intensity and stability were compared to those of residual magnetization following zero-field cooling (TRM₀) from above the Curie point of kamacite (Ni---Fe). The latter criterion separates the role of an external magnetic field (of 0.43 Oe) at cooling from intrinsic contributions to magnetic grain alignments, due to accretionary, metamorphic or shock-oriented petrofabrics.

In some chondrites (e.g., Brownfield, H3B; Holyoke, H4C; Farley, H5A), a surprisingly large (10% NRM) and stable TRM₀ proved so similar to NRM and TRM, that sizeable spurious “paleofields” — comparable to paleointensities obtained — were derived by the standard method for zero-field cooling. In other chondrites, with negligible TRM₀ (1% of NRM) and irregular AF demagnetization curves, more reliable paleofield strengths in the range 0.01–0.09 Oe were obtained (e.g., Cavour, H6C). These seem representative of magnetic fields at the end of metamorphism intervals (10⁷ years after accretion) and/or at post-shock cooling. Thus, field strengths obtained from ordinary chondrites are typically weaker (by factors of 10–100) than those reliably determined from carbonaceous chondrites and ureilites, suggesting temporal decay of nebular magnetic fields, from the end of accretion until the end of metamorphism and early catastrophic-collisional stages.