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Mountain glaciers are highly sensitive to climate change. However, the extent to which glaciers capture regional to hemisphere‐scale atmospheric processes remains uncertain, hindering paleoclimatic interpretations derived from moraine‐based glacier reconstructions. Here, we evaluate how mid‐latitude glacier systems monitor climate by comparing climate reanalysis products with glacier annual equilibrium line altitude (ELA) elevations from the antipodal Southern Alps of New Zealand and European Alps. We find significant regional and hemispheric correlations between glacier annual ELA and summer tropospheric temperatures. Annual ELA also exhibit positive correlations with the latitude of the westerly jets in both hemispheres. These results indicate that westerly wind‐belt latitude modulates the proportion of cold versus warm air masses influencing these glacier systems. These results highlight the sensitivity of mid‐latitude glaciers to atmospheric temperatures and circulation, with implications for interpreting moraine‐based paleoclimate reconstructions. Combined impacts of ongoing tropospheric warming and poleward‐shifting westerlies will likely accelerate recession of mid‐latitude glaciers. Plain Language Summary: Mountain glaciers respond to climate change by gaining mass when the climate cools and losing mass when the climate warms. However, the extent to which these glacial fluctuations are reflective of local, regional, and hemispheric climate variations is less clear, hindering climatic interpretation of paleo‐glacier reconstructions developed from glacial landforms. This study evaluates the climatic footprint monitored by antipodal mid‐latitude glacier populations by comparing gridded reconstructions of global temperature and wind changes with glacier annual snowline elevations in the Southern Alps of New Zealand and annual equilibrium line altitude elevations in the European Alps. Our results indicate that (a) these glacier systems co‐vary with atmospheric temperatures on regional and even hemispheric scales throughout all levels of the troposphere, and (b) the latitudes of the westerly wind belts are important for regulating the proportion of cold versus warm air masses influencing glacier mass‐balance. Altogether, our results indicate that mid‐latitude mountain glacier fluctuations reflect temperature changes integrated over large regions of the atmosphere. With ongoing climate change, the combination of global atmospheric warming and poleward‐shifting westerlies is likely to accelerate recession of mid‐latitude glaciers in both hemispheres. Key Points: Mid‐latitude glacier annual equilibrium line altitude corresponds to broad regions of atmospheric temperatureMid‐latitude glacier annual equilibrium line altitude is sensitive to latitudinal shifts of the mid‐latitude westerliesThe influence of the westerlies on glaciers has important implications for interpreting past and predicting future climate change [ABSTRACT FROM AUTHOR]

The Paris Agreement asserts that greenhouse gas emission pathways should be consistent with holding the increase in global temperature below 1.5 °C, or 2 °C above pre-industrial levels. The purpose of this paper is to assess the economic impact of this agreement on the cattle and food product sectors of New Zealand. We used a general equilibrium approach to evaluate the economic impacts, and the Global Timber Model to estimate forestry carbon sequestration. We simulated eight scenarios where we allow accounting/not accounting for sequestration, pricing/not pricing agricultural emissions, and linking/not linking the New Zealand Emissions Trading Scheme (ETS) with the European Union ETS. We found that significant negative impacts occur if sequestration is not accounted, the ETS remains unlinked and agriculture is priced. Competitiveness, in turn, is not significantly affected if sequestration is accounted, regardless of the linking scheme of the ETS. [ABSTRACT FROM AUTHOR]

Historical evidence shows that the mean temperatures in the main cities in New Zealand have not changed significantly since records began in the 1860s1-4.Recently, the New Zealand Institute for Water and Air Research11, after a thorough Review, has presented a revised temperature anomaly chart for the average temperatures of seven of the major urban centres in New Zealand which shows that there has been an increasing temperature trend of 0.91°C per century since 1909.This paper analyses the Review and concludes that the results are compatible with the historic view of no significant change since records began. Although the trends found are explained by natural causes their statistical significance is very low because of the unsuitability of the "neighbour station" comparison used, and the inaccuracy of the measured and processed temperature measurements. [ABSTRACT FROM AUTHOR]

The warming trend over the last century in the northern hemisphere (NH) was interrupted by cooling from ad 1940 to 1975, a period during which the southern hemisphere experienced pronounced warming. The cause of these departures from steady warming at multidecadal timescales are unclear; the prevailing explanation is that they are driven by non-uniformity in external forcings but recent models suggest internal climate drivers may play a key role. Paleoclimate datasets can help provide a long-term perspective. Here we use tree-rings to reconstruct New Zealand mean annual temperature over the last 550 years and demonstrate that this has frequently cycled out-of-phase with NH mean annual temperature at a periodicity of around 30-60 years. Hence, observed multidecadal fluctuations around the recent warming trend have precedents in the past, strongly implicating natural climate variation as their cause. We consider the implications of these changes in understanding and modelling future climate change. [ABSTRACT FROM AUTHOR]

We investigated seasonal variation in dark respiration and photosynthesis by measuring gas exchange characteristics on Pinus radiata and Populus deltoides under field conditions each month for 1 year. The field site in the South Island of New Zealand is characterized by large day-to-day and seasonal changes in air temperature. The rate of foliar respiration at a base temperature of 10 °C ( R10) in both pine and poplar was found to be greater during autumn and winter and displayed a strong downward adjustment in warmer months. The sensitivity of instantaneous leaf respiration to a 10 °C increase in temperature ( Q10) was also greater during the winter period. The net effect of this strong acclimation was that the long-term temperature response of respiration was essentially flat over a wide range of ambient temperatures. Seasonal changes in photosynthesis were sensitive to temperature but largely independent of leaf nitrogen concentration or stomatal conductance. Over the range of day time growth temperatures (5–32 °C), we did not observe strong evidence of photosynthetic acclimation to temperature, and the long-term responses of photosynthetic parameters to ambient temperature were similar to previously published instantaneous responses. The ratio of foliar respiration to photosynthetic capacity ( Rd/ Asat) was significantly greater in winter than in spring/summer. This indicates that there is little likelihood that respiration would be stimulated significantly in either of these species with moderate increases in temperature – in fact net carbon uptake was favoured at moderately higher temperatures. Model calculations demonstrate that failing to account for strong thermal acclimation of leaf respiration influences determinations of leaf carbon exchange significantly, especially for the evergreen conifer. [ABSTRACT FROM AUTHOR]

A representative temperature record for New Zealand based on station data from 1853 onward is used in conjunction with four coupled climate models to investigate the causes of recent warming over this small midlatitude country. The observed variability over interannual and decadal time scales is simulated well by the models. The variability of simulated 50-yr trends is consistent with the very short observational record. For a simple detection analysis it is not possible to separate the observed 30- and 50-yr temperature trends from the distribution created by internal variability in the model control simulations. A pressure index that is representative of meridional flow (M1) is used to show that the models fail to simulate an observed trend to more southerly flows in the region. The strong relationship between interannual temperature variability and the M1 index in both the observations and the models is used to remove the influence of this circulation variability from the temperature records. Recent 50-yr trends in the residual temperature record cannot be explained by natural climate variations, but they are consistent with the combined climate response to anthropogenic greenhouse gas emissions, ozone depletion, and sulfate aerosols, demonstrating a significant human influence on New Zealand warming. This result highlights the effect of circulation variability on regional detection and attribution analyses. Such variability can either mask or accelerate human-induced warming in observed trends, underscoring the importance of determining the underlying forced trend, and the need to adequately capture regional circulation effects in climate models. [ABSTRACT FROM AUTHOR]

If global warming is accelerating, then one might expect temperatures for most stations to be accelerating and perhaps variability to be increasing. In this study, we examine 57 New Zealand temperature time series for evidence of non-linearity and changing variability. These correspond to time series for annual minima, annual means and annual maxima for 19 stations. Estimation is by an extended least-squares method. We find a surprising diversity of behaviour of these series – presumably reflecting their different geographic factors as well as series length. We give evidence of regions where temperatures are decreasing. For series where a linear trend is significant, it is downwards in about one third of the cases. This proportion was higher in the South Island, especially for series of minima. Where a non-linear trend is significant, temperatures are decelerating in about one half of the cases. The ratio of downward to upward trends is highest among annual maxima and South Island minima and smallest in annual means. Where a linear trend in the variability is significant, it is decreasing in 13 cases and increasing in 5 cases, although possibly this is partly due to poorer quality data last century. Where a non-linear trend in the variability is significant, variability is decelerating in about two thirds of the cases. The results are used to project upper and lower return levels of minima, means and maxima for each of the series to the year 2010. [ABSTRACT FROM AUTHOR]

A United Nations Framework Convention on Climate Change (UNFCCC) Joint Implementation (JI) host country has to make sure that JI projects are additional to avoid extra costs to generate the reductions necessary to cover the deduction of Emission Reduction Units (ERUs) from the country's Kyoto Protocol emissions budget. A tender of ERUs by the government allows to generate additional reductions beyond the ERUs issued if it thoroughly checks project additionality. The government of New Zealand is running a tender for JI projects under the title ‘Projects to Reduce Emissions’ since 2003. In two rounds, 10 million ERUs have been awarded and several projects have already entered into contracts with European buyers. The ratio of ERUs awarded to reductions achieved was 0.8 in the second tender. However it remains to be seen whether the additionality test of this tender is sufficient to exclude clearly non-additional projects. [ABSTRACT FROM AUTHOR]