Human-caused environmental change: Impacts on plant diversity and evolution

Human-caused environmental changes are creating regional combinations of environmental conditions that, within the next 50 to 100 years, may fall outside the envelope within which many of the terrestrial plants of a region evolved. These environmental modifications might become a greater cause of global species extinction than direct habitat destruction. The environmental constraints undergoing human modification include levels of soil nitrogen, phosphorus, calcium and pH, atmospheric CO2, herbivore, pathogen, and predator densities, disturbance regimes, and climate. Extinction would occur because the physiologies, morphologies, and life histories of plants limit each species to being a superior competitor for a particular combination of environmental constraints. Changes in these constraints would favor a few species that would competitively displace many other species from a region. In the long-term, the “weedy” taxa that became the dominants of the novel conditions imposed by global change should become the progenitors of a series of new species that are progressively less weedy and better adapted to the new conditions. The relative importance of evolutionary versus community ecology responses to global environmental change would depend on the extent of regional and local recruitment limitation, and on whether the suite of human-imposed constraints were novel just regionally or on continental or global scales.

Coral reefs in a century of rapid environmental change

Coral reefs are the most diverse marine ecosystem and embrace possibly millions of plant, animal and protist species. Mutualistic symbioses are a fundamental feature of coral reefs that have been used to explain their structure, biodiversity and existence. Complex inter-relationships between hosts, habitats and symbionts belie closely coupled nutrient and community dynamics that create the circumstances for something from nothing (or the oasis in a nutrient desert). The flip side of these dynamics is a close dependency between species, which results in a series of non-linear relationships as conditions change. These responses are being highlighted as anthropogenic influences increase across the world's tropical and subtropical coastlines. Caribbean as well as Indo-Pacific coral populations are now in a serious decline in many parts of the world. This has resulted in a significant reorganization of how coral reef ecosystems function. Among the spectra of changes brought about by humans is rapid climate change. Mass coral bleaching - the loss of the dinoflagellate symbionts from reef-building corals - and mortality has affected the world's coral reefs with increasing frequency and intensity since the late 1970s. Mass bleaching events, which often cover thousands of square kilometres of coral reefs, are triggered by small increases (+1-3degreesC) in water temperature. These increases in sea temperature are often seen during warm phase weather conditions (e.g. ENSO) and are increasing in size and magnitude. The loss of living coral cover (e.g. 16% globally in 1998, an exceptionally warm year) is resulting in an as yet unspecified reduction in the abundance of a myriad of other species. Projections from general circulation models (GCM) used to project changes in global temperature indicate that conditions even under the mildest greenhouse gas emission scenarios may exceed the thermal tolerances of most reef-building coral communities. Research must now explore key issues such as the extent to which the thermal tolerances of corals and their symbionts are dynamic if bleaching and disease are linked; how the loss of high densities of reef-building coral will affect other dependent species; and, how the loss of coral populations will affect the millions of people globally who depend on coral reefs for their daily survival.

Climate change manipulations show Antarctic flora is more strongly affected by elevated nutrients than water

Climate change is expected to affect the high latitudes first and most severely, rendering Antarctica one of the most significant baseline environments for the study of global climate change. The indirect effects of climate warming, including changes to the availability of key environmental resources, such as water and nutrients, are likely to have a greater impact upon continental Antarctic terrestrial ecosystems than the effects of fluctuations in temperature alone. To investigate the likely impacts of a wetter climate on Antarctic terrestrial communities a multiseason, manipulative field experiment was conducted in the floristically important Windmill Islands region of East Antarctica. Four cryptogamic communities (pure bryophyte, moribund bryophyte, crustose and fructicose lichen-dominated) received increased water and/or nutrient additions over two consecutive summer seasons. The increased water approximated an 18% increase in snow melt days (0.2 degrees C increase in temperature), while the nutrient addition of 3.5g Nm(-2) yr(-1) was within the range of soil N in the vicinity. A range of physiological and biochemical measurements were conducted in order to quantify the community response. While an overall increase in productivity in response to water and nutrient additions was observed, productivity appeared to respond more strongly to nutrient additions than to water additions. Pure bryophyte communities, and lichen communities dominated by the genus Usnea, showed stronger positive responses to nutrient additions, identifying some communities that may be better able to adapt and prosper under the ameliorating conditions associated with a warmer, wetter future climate. Under such a climate, productivity is overall likely to increase but some cryptogamic communities are likely to thrive more than others. Regeneration of moribund bryophytes appears likely only if a future moisture regime creates consistently moist conditions.

Rethinking change:downsizing businesses, changing behaviours and still managing to come out on top

As an indicator of global change and shifting balances of power, every September in Dalian, China, the World Economic Forum meets. The subject in 2011 – Mastering Quality Growth. On the agenda is pursuing new frontiers of growth linked to embracing disruptive innovation. With growth coming from emerging markets, and European and North American economies treading water, many firms in the West are facing the reality of having to not just downsize but actually close manufacturing operations and re-open them elsewhere, where costs are lower, to remain competitive. There are thousands of books on “change management”. Yet very few of these devote much time to downsizing preferring to talk about re-engineering or restructuring. What lessons are available from the past to achieve a positive outcome from what will inevitably be something of a human, as well as an economic, tragedy. The authors reached three fundamental conclusions from their experience and research in facility closure management within Vauxhall, UK: put your people first, make sure you keep running the business and manage your legacy. They devlop the ideas into a new business model linked to the emotions of change.

Bioenergy and climate change mitigation : an assessment

Date of Acceptance: 08/05/2014 Acknowledgements The authors are indebted to Julia Römer for assisting with editing several hundred references. Helmut Haberl gratefully acknowledges funding by the Austrian Academy of Sciences (Global Change Programme), the Austrian Ministry of Science and Research (BMWF, proVision programme) as well as by the EU-FP7 project VOLANTE. Carmenza Robledo-Abad received financial support from the Swiss State Secretariat for Economic Affairs.

Decoupling of Greenhouse Gas Emissions from Global Agricultural Production : 1970 - 2050

This article is protected by copyright. All rights reserved. Acknowledgements We thank Tamara Ben-Ari and Jean-Francois Soussana, from INRA in France, for their valuable contributions to the early development stage of this project. We also owe great acknowledge to Prof. Ib Skovgaard, University of Copenhagen, for giving essential assistance in developing the methods for decomposing emission changes. We also thank the Centre for Regional Change in the Earth System (CRES, www.cres-centre.dk) and the Department of Plant- and Environmental Sciences, University of Copenhagen, for funding the work.

Bioenergy and climate change mitigation : an assessment

Date of Acceptance: 08/05/2014 Acknowledgements The authors are indebted to Julia Römer for assisting with editing several hundred references. Helmut Haberl gratefully acknowledges funding by the Austrian Academy of Sciences (Global Change Programme), the Austrian Ministry of Science and Research (BMWF, proVision programme) as well as by the EU-FP7 project VOLANTE. Carmenza Robledo-Abad received financial support from the Swiss State Secretariat for Economic Affairs.

Simulation of greenhouse gases following land-use change to bioenergy crops using the ECOSSE model : a comparison between site measurements and model predictions

This work contributes to the ELUM (Ecosystem Land Use Modelling & Soil Carbon GHG Flux Trial) project, which was commissioned and funded by the Energy Technologies Institute (ETI). We acknowledge the E-OBS data set from the EU-FP6 project ENSEMBLES (http://ensembles-eu.metoffice.com) and the data providers in the ECA&D project (http://www.ecad.eu).

Global impacts of the 1980s regime shift

Despite evidence from a number of Earth systems that abrupt temporal changes known as regime shifts are important, their nature, scale and mechanisms remain poorly documented and understood. Applying principal component analysis, change-point analysis and a sequential t-test analysis of regime shifts to 72 time series, we confirm that the 1980s regime shift represented a major change in the Earth's biophysical systems from the upper atmosphere to the depths of the ocean and from the Arctic to the Antarctic, and occurred at slightly different times around the world. Using historical climate model simulations from the Coupled Model Intercomparison Project Phase 5 (CMIP5) and statistical modelling of historical temperatures, we then demonstrate that this event was triggered by rapid global warming from anthropogenic plus natural forcing, the latter associated with the recovery from the El Chichón volcanic eruption. The shift in temperature that occurred at this time is hypothesized as the main forcing for a cascade of abrupt environmental changes. Within the context of the last century or more, the 1980s event was unique in terms of its global scope and scale; our observed consequences imply that if unavoidable natural events such as major volcanic eruptions interact with anthropogenic warming unforeseen multiplier effects may occur.

Global impacts of the 1980s regime shift

Despite evidence from a number of Earth systems that abrupt temporal changes known as regime shifts are important, their nature, scale and mechanisms remain poorly documented and understood. Applying principal component analysis, change-point analysis and a sequential t-test analysis of regime shifts to 72 time series, we confirm that the 1980s regime shift represented a major change in the Earth's biophysical systems from the upper atmosphere to the depths of the ocean and from the Arctic to the Antarctic, and occurred at slightly different times around the world. Using historical climate model simulations from the Coupled Model Intercomparison Project Phase 5 (CMIP5) and statistical modelling of historical temperatures, we then demonstrate that this event was triggered by rapid global warming from anthropogenic plus natural forcing, the latter associated with the recovery from the El Chichón volcanic eruption. The shift in temperature that occurred at this time is hypothesized as the main forcing for a cascade of abrupt environmental changes. Within the context of the last century or more, the 1980s event was unique in terms of its global scope and scale; our observed consequences imply that if unavoidable natural events such as major volcanic eruptions interact with anthropogenic warming unforeseen multiplier effects may occur.