Cambiamenti Climatici: Evidenze Scientifiche Globali ed Effetti sulla Regione Euro-Mediterranea

Silvio Gualdi

Centro Euro-Mediterraneo sui Cambiamenti Climatici

“IL CLIMA CHE CAMBIA: cambiamenti climatici, impatti e politiche climatiche in italia”

#climatechange, #climachecambia, #greeneconomy

27 novembre 2015, Auditorium Santa Margherita, Ca’ Foscari, Venezia

Global Trends

Direct observations

European Environment Agency, 2015 Indicator Assessment | Data and maps

Direct observations

Each line represents an independently derived estimate of change in the climate element.

Multiple complementary indicators of a changing global climate

IPCC WG1-AR5

Global Trends

Attribution: Disentangling the human influence from natural variability

IPCC WG1-AR4

Global Trends

IPCC WG1-AR5

Scenarios and Projections

EMISSIONS

CONCENTRATIONS

IPCC scenarios of greenhouse gases emissions and concentrations (used to perform the IPCC climate projections)

Modified from IPCC WG1-AR5

Global Projections

Annual mean surface air temperature change compared to the 1986-2005 reference period

RCP8.5 2045-2065 RCP8.5 2081-2100

Modified from IPCC WG1-AR5

2046-2065 DJF 2081-2100 DJF

2046-2065 JJA 2081-2100 JJA

Seasonal mean Precipitation change (RCP8.5) compared to the 1986-2005 reference period

Global Projections

Projected changes (wrt 1981-2000) in annual maximum five-day precipitation and of maximum number of consecutive dry days

Modified from IPCC WG1-AR5

Change in Precipitation Extremes

Global Projections

Annual precipitation is generally projected to increase in northern Europe and to decrease in southern Europe. Projected decrease is the strongest in southern Europe in summer.

Focus on the European Continent

Projected changes in annual (left) and summer (right) precipitation (%) in the period 2071-2100 compared to the baseline period 1971-2000 for the forcing scenario RCP 8.5. Model simulations are based on the multi-model ensemble average of RCM simulations from the EURO-CORDEX initiative.

Projected Mean Precipitation Change

http://www.eea.europa.eu/data-and-maps/indicators/

Projected Heavy Precipitation Change

Focus on the European Continent

Adapted from D. Jacob, C3S workshop, Reading 2015

Focus on the European Continent

Projected Mean Temerature Change

http://www.eea.europa.eu/data-and-maps/indicators/

Projected changes in near-surface air temperature (°C) in the period 2071-2100 compared to the baseline period 1971-2000 for the forcing scenarios RCP 8.5 (Data source EURO-CORDEX).

Heat waves are projected to become more frequent and last longer across Europe during this century (Fischer and Schär 2010, IPCC 2013, Russo et al. 2014)

Projected changes in Temperature Extremes

Focus on the European Continent

Trends in Warm Days (Tmax > 90%) Trends in Cold Nights (Tmin > 10%)

http://www.eea.europa.eu/data-and-maps/indicators/

Athens Case Study: heat-waves

(Goodess et al 2013)

Focus on the European Continent

Uncertainty

GLOBAL MEAN SURFACE TEMPERATURE CHANGE

Knutti & Janek 2012

RELATIVE IMPORTANCE OF DIFFERENT UNCERTAINTIES

Modified from IPCC WG1-AR5

Warming of the climate system is unequivocal, as is now evident from observations.

Most of the observed warming since the mid-20th century is very likely due to the observed increase in anthropogenic greenhouse gas concentrations.

Continued greenhouse gas emissions would cause further warming and induce many changes in the global climate system during the 21st century.

The 21st century climate change would very likely be larger than those observed during the 20th century with substantial impacts on human societies and ecosystems primarily through changes in the water cycle.

Summary and Conclusions

Extreme events such as heavy precipitation and heat wave events are likely to increase in most parts of Europe.

During the period 1980-2012 parts of Europe experienced extreme heat-waves (summers of 2003, 2006, 2007 and 2010). Such heat waves are projected to become the norm in the second half of the 21st century under high forcing scenario (RCP8.5).

Grazie