What is the role of land-use change for the present, past, and future evolution of the Earth?

The elements for possible consideration in this question have global dimensions. These elements range from carbon storage, food production, the water cycle, climate (including albedo), human societies, to migration. Answering this question requires full Earth system models that are not yet up to the task, in part because the processes that connect key elements of these models are not well constrained or understood. There are many causes of these deficiencies, including the fact that observing land-use change is difficult on the time and space scales needed for documenting and understanding key processes.

How can we boost agricultural output and improve rural livelihoods in the developing world (especially sub-Saharan Africa) without attendant land/forest degradation and resultant biodiversity loss?

Sub-Saharan Africa is the poorest region of the world and experiencing high rates of land degradation, desertification, forest degradation and loss. The ecology-welfare link in this part of the world is very strong and most people live outside formal institutions and markets. Declining crop yields have meant agricultural expansion and in places like the Eastern Afromontane Hotspot this means large potential for the loss of endemic species. Livelihoods here are also closely tied to annual rainfall patterns and any near term changes in these as a result of climate change may also rationalize further agricultural expansion (e.g. to areas with more stable rainfall, or as an insurance mechanism to ensure a certain level of output). Here we have a nexus of severe poverty, high biodiversity, poor agricultural productivity, climate vulnerability and potential loss of carbon stored in woodland and forest ecosystems.

How will humanity manage peak oil and climate change impacts and promote an ordered and gradual transition to low carbon economies?

The strong environmental effects of greenhouse gas emissions derived from oil use and the negative socio-economic consequences of future oil scarcity make it urgent to shift to alternative affordable energy sources. A recent assessment of the International Energy Agency, an OECD prestigious institution, alerts that oil shortage and increased energy costs can easily be an immediate reality after the current financial crisis if massive and strategic investments in oil industry are not rapidly and massively implemented.

Multiple economic, scientific, technological and political pathways should be implemented to achieve this global energy transition. States should empower their national strategies to improve the efficiency in energy generation, transmission and consumption and thus reduce progressively carbon emissions. States should also facilitate the massive deployment of renewable energies and public transport, promote the progressive electrification of the car industry, and globally shift to sustainable strategies in many other economic sectors. At the international level, governments should rapidly promote multilateral and bilateral cooperative agreements on energy and climate policies. In addition, states might promote the creation of a United Nations international programme to facilitate and coordinate a world-wide ordered and non-traumatic transition to low-carbon and energy-efficient economie. This UN international programme could develop or facilitate multilateral regulatory agreements to avoid the emergence of speculative dynamics and volatility on oil prices that ultimately damage economic stability and increase ongoing global food-security crisis. Finally, I advocate for a much greater scientific effort urgently placed on the interactions between peak oil, climate change and global society change. The scale, urgency and severity of peak oil and climate change mean that no action is too small to matter, too large to contemplate, or too soon to begin. There is not much time left.

How to establish balanced use of agricultural land and better ecological function?

Agricultural land occupies about 10% of total land area, pastures not included. Its ecological influence (nutrient cycles, carbon storage, energy, water, biodiversity) is considerably larger. The sector is growing both in extent and intensity. The world needs good ecological function of this sector.

The main task for agriculture is to produce food for mankind. The present main policy is that agricultural production like other “industries” shall be governed by market forces, in reality price competition on a global scale (within a very weak concept “Good Agricultural Practice).

However, there is a contradiction. Factors favouring market competitiveness are specialization and adaptability ( we could say shortsightedness). Factors favouring ecological function are diversity and longterm consideration, exactly the opposite. There are environmental programs, but they are not accepted world wide. They are criticized for distorting competitiveness in both directions.

With a few sacrifices in economy and production (if any in the long term) agriculture could develop much better ecological function even with present knowledge and technology (Background: www.greengard.se/Eco-efficiency.htm . But for the farm manager such measures compromise shortterm competitiveness. He should not be expected to disobey the rules the society has given him.

The research task (economic/political/agronomic) is to create a background for a framework including “ecological values” as drivers for development. Let market economy work also on the ecological side. It should go beyond present attempts with carbon trading etc, and include for instance nutrient and water efficiency, diversity and landscape function.

Göte Bertilsson, Agr system consultant, Sweden

What is the interannual variability in the hydrological cycle over rainfed agriculture areas?

Most of our food is produced from the rainfed areas. Disturbing the existing system could cause great frustrations to the growers, and possible food deficiencies in the future.

What are the consequences of land cover and land use change for human societies and the sustainability of ecosystems?

The environment of the Earth has many close connections and relationships with human activity. It is also now more widely recognized that a profound transformation of the Earth’s environment is taking place and that many of these changes are the result of human action. Growing world population and increasing wealth are driving demands for more food production. Croplands and pastures occupies today roughly 40% of the land surface and global land cover and is according to the Millennium Ecosystem Assessment (MA) the main modification humanity makes to land cover, and therefore a main driver of ecological change, and biodiversity loss at the global scale.

Current trends in land use allow humans to appropriate an ever-larger fraction of the biosphere’s goods and services while simultaneously diminishing the capacity of global ecosystems to sustain food production, maintain freshwater and forest resources, regulate climate and air quality, and mediate infectious diseases…
Modern landuse practices, while increasing the short-term supplies of material goods, may undermine many ecosystem services in the long run, even on regional and global scales. Confronting the global environmental challenges of land use will require assessing and managing inherent trade-offs between meeting immediate human needs and maintaining the capacity of ecosystems to provide goods and services in the future. Assessments of trade-offs must recognize that land use provides crucial social and economic benefits, even while leading to possible long-term declines in human welfare through altered ecosystem functioning.
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How can we provide food to humanity while sustaining animal well-being and biodiversity ?

The animal well being can not be set aside in favor of human well being. Both are interconnected and interdependent. Livestock farming today is awful and does not seem to improve. The same remarks can also address the agricultural field. If we can establish a parallel between biodiversity and humanity qualities and living conditions, what will the future look like ?

How will agricultural biodiversity losses predicted by climate change impact agriculture, rural development and food security?

Agricultural biodiversity (agrobiodiversity) as an important component of biodiversity provides a number of benefits associated with production and productivity, agro-ecosystem function, and human well-being. At the same time it is well known that the climate change will be the main driver of loss of biodiversity in general and of agrobiodiversity in particular. This impact will be different for the different components of agricultural biodiversity. Thus the undertaking predictive modelling of impact of possible losses and distribution of agricultural biodiversity most important to food security on agriculture and rural development will significantly contribute to address food security needs in face of global warming.

What are the consequences of ground water reduction on agriculture?

I asked this question and I am concerned that population is growing therefor its food demand and more agriculture productivity means somehow losing soil strength and soil water (soil productivity). This may affect climate regionally. How to address such problem in next decade. If human want to survive than we have to address such question in next decade first rather than discussing water cycle and global warming as they are seems to be periodic.

How do we meet the human wellbeing requirements (e.g. food and nutritional security, health, livelihoods) of current and future human populations without increasing pressure on already vulnerable ecosystems?

Increasing evidence suggests that demands on food production are likely to reach a peak mid-century. At the same time, our ability to produce and transport sufficient food is predicted to be reduced by climate change (temperature and water dynamics), carbon costs (chemicals, transport), and the loss of land to energy production.

There will therefore be increasing pressure on:
• natural resources (land and associated water and soil, biodiversity), leading to trade-offs for ecosystem service provisioning (with impacts on livelihoods, ecosystem and human health, security) and other land uses (agriculture, biofuels, urban planning, conservation, recreation)
• agricultural practice leading for the need for new and innovative techniques and technologies, and the concomitant risks for environmental and human health

To stand a chance of tackling these inter-related issues, mechanisms and funding for regional and global projects that move beyond assessment are required. Projects should be interdisciplinary and participatory incorporating researchers, practitioners and the people whose wellbeing is under investigation. Such work should not only allow conceptual and theoretical development in the fields of environmental and sustainability science but must also have impact on the ground, creating opportunities for improved human wellbeing and increased resilience not just for now, but into the future also.