CC: Impatti Ambiente fisico

CLIMATOLOGIA

Prof. Carlo Bisci

Direct and indirect effects of non-climate drivers

Areal extent of Chacaltaya Glacier, Bolivia, from 1940 to 2005

Glaciers

Water

Historical and recent measurements from Lake Tanganyika, East Africa: (a) upper mixed layer (surface water) temperatures;

(b) deep-water (600 m) temperatures;

(c) depth of the upper mixed layer. Triangles represent data collected by a different method. Error bars represent standard deviations

Impact of human activities on freshwater resources and their management, with climate change being only one of multiple pressures

Change in annual runoff relative to 1900-70, in percent

Erosion and sediment transport•change in the erosive power of rainfall; •changes in plant canopy caused by shifts in plant biomass production associated with moisture regime;

•changes in litter cover on the ground caused by changes in plant residue decomposition rates driven by temperature, in moisture-dependent soil microbial activity, and in plant biomass production rates;

•changes in soil moisture due to shifting precipitation regimes and evapotranspiration rates, which changes infiltration and runoff ratios;

•soil erodibility changes due to a decrease in soil organic matter concentrations (which lead to a soil structure that is more susceptible to erosion) and to increased runoff (due to increased soil surface sealing and crusting);

•a shift in winter precipitation from non-erosive snow to erosive rainfall due to increasing winter temperatures;

•melting of permafrost, which induces an erodible soil state from a previously non-erodible one;

•shifts in land use made necessary to accommodate new climatic regimes.

Annual crop water demand and water supply for Trout Creek, Okanagan region, Canada, modelled for 1961 to 1990 (historic) and three 30-year time slices in the future. Each dot represents one year. Drought supply threshold is represented by the vertical line, maximum observed demand is shown as the horizontal line

Relative costs per unit of water saved or supplied in the Okanagan region, British Columbia

Impact of population growth and climate change on the number of people (in millions) living in water-stressed river basins (defined as per capita renewable water resources of less than 1,000 m3/yr) around 2050

Cross-scale issues in the integrated water management of the Colorado River Basin

Some adaptation options for water supply and demand (the list is not exhaustive)

Potential contribution of the water sector to attain the Millennium Development Goals.

 Illustrative map of future climate change impacts on freshwater which are a threat to the sustainable development of the affected regions. Background map: Ensemble mean change of annual runoff, in percent, between present (1981 to 2000) and 2081 to 2100 for the SRES A1B emissions scenario.

Sea

Long-term changes in the mean number of marine zooplankton species per association in the North Atlantic from 1960 to 1975 and from 1996 to 1999. The number of temperate species has increased and the diversity of colder-temperate, sub-Arctic and Arctic species has decreased in the North Atlantic. The scale (0 to 1) indicates the proportion of biogeographical types of species in total assemblages of zooplankton.

Shoreline

Selected global non-climatic environmental and socio-economic trends relevant to coastal areas for the SRES storylines. Regional and local deviations are expected.

Main climate drivers for coastal systems, their trends due to climate change, and their main physical and ecosystem effects. (Trend: ↑ increase; ? uncertain; R regional variability).

Increases in the height (m) of the 50-year extreme water level.

(b) Around the UK for the A2 scenario in the 2080s

(a) In the northern Bay of Bengal under the IS92a climate scenario in 2040-2060 (K – Kolkata (Calcutta), C – Chittagong)

Flooding around Cairns, Australia during the >100 year return-period event under current and 2050 climate conditions based on a 2xCO2 scenario.

Relative vulnerability of coastal deltas as shown by the indicative population potentially displaced by current sea-level trends to 2050.

(Extreme = >1 million; High = 1 million to 50,000; Medium = 50,000 to 5,000).

Summary of climate-related impacts on socio-economic sectors in coastal zones.

X = strong; x= weak; – = negligible or not established.

Estimates of the population (in millions) of the coastal flood plain in 1990 and the 2080s (following Nicholls, 2004). Assumes uniform population growth; net coastward migration could substantially increase these numbers.

Indicative estimates of regional exposure as a function of elevation and baseline (1995) socio-economics. MER – market exchange rates

Estimates of the average annual number of coastal flood victims (in millions) due to sea-level rise. Assumes no change in storm intensity and evolving protection. Range reflects uniform population growth. Base= baseline without sea-level rise; aSLR = additional impacts due to sea-level rise.

Real estate damage costs related to flood levels for the Rio de la Plata, Argentina

Health effects of climate change and sea-level rise in coastal areas.

Key hotspots of societal vulnerability in coastal zones.

Causes, selected consequences and the total costs of an assumed sea-level rise, for developing and developed countries, and as a global total.

Recent extreme events: lessons for coastal adaptation to climate change

•An effective early warning communication and response system can reduce death and destruction;

•Hazard awareness education and personal hazard experience are important contributors to reducing community vulnerability;

•Many factors reduce the ability or willingness of people to flee an impending disaster, including the warning time, access and egress routes, and their perceived need to protect property, pets and possessions;

•Coastal landforms (coral reefs, barrier islands) and wetland ecosystems (mangroves, marshes) provide a natural first line of protection from storm surges and flooding, despite divergent views about the extent to which they reduce destruction;•Recurrent events reduce the resilience of natural and artificial defences;

•In the aftermath of extreme events, additional trauma occurs in terms of dispossession and mental health;

•Uncoordinated and poorly regulated construction has accentuated vulnerability;

•Effective disaster prevention and response rely on strong governance and institutions, as well as adequate public preparedness.

Major impediments to the success of adaptation in the coastal zone.

Selected tools that support coastal adaptation assessments and interventions.

Evolution of planned coastal adaptation practices.

Selected information on costs and benefits of adaptation.