Precipitation - outlook from UNFCCC

Assessment versions

Published (reviewed and quality assured)

• No published assessments

Rationale

Justification for indicator selection

Precipitation is a major component of the hydrological cycle. The amount and spatial distribution of European precipitation is strongly influenced by circulation patterns. Most precipitation over Europe is connected with the advection of maritime air masses from the Atlantic and the Mediterranean. The combination of changes in the precipitation regime and increases in air temperature can lead to extreme hydrological evens such a flooding and droughts. Some systems or sectors, closely connected with the hydrological cycle, are very sensitive to the combined effects of higher temperatures and changed precipitation characteristics. Within limits and at a cost, adaptation to many of the impacts is possible. These options will be briefly mentioned in the individual indicator sections.

Homogenous time series of monthly precipitation data and interpolation and gridding methods enable  analysis of various periods from 1901 on various temporal and spatial scales. However, differences between climate models for future precipitation projections indicate higher uncertainty for regional and seasonal results than for temperature projections and observed precipitation trends. (EEA Report / No4/2008. Impacts of Europe's changing climate -- 2008 indicator-based assessment).

Scientific references

• No rationale references available

Indicator definition

Precipitation (total volume of water precipitated to a certain surface area for a given period of time) means water, in either liquid or solid state, falling out of the clouds or depositing from the air on the land surface, on various materials or plants. Atmospheric precipitation may take the form of rain, drizzle, snow, sleet, snow pellets or small hail, hail or sleet.

Units

The indicator is measured by the layer thickness of the precipitated water in millimetres (mm) as a percentage of perennial standards.

Policy context and targets

Context description

There is no documents providing the indicator as a target. However, precipitation projections can be used for complex climate projections and be presented in a wide range of policies and documents concerning climate change measurements.

Over a decade ago, most countries joined an international treaty -- the United Nations Framework Convention on Climate Change (UNFCCC) -- to begin to consider what can be done to reduce global warming and to cope with whatever temperature increases are inevitable. Recently, a number of nations have approved an addition to the treaty: the Kyoto Protocol. The Kyoto Protocol, an international and legally binding agreement to reduce greenhouse gases emissions world wide, entered into force on February 16th 2005. The 1997 Kyoto Protocol shares the Convention's objective, principles and institutions, but significantly strengthens the Convention by committing Annex I Parties to individual, legally-binding targets to limit or reduce their greenhouse gas emissions.

To date 40 countries in the Pan-European region ratified the Kyoto Protocol, notably:  Annex I: Belarus,Bulgaria,Croatia, Romania,  Russian Federation,Ukraine, EU 25. Non-Annex I countries:Albania,Armenia,Azerbaijan,Georgia,Kyrgyzstan, Former Yugoslavian Republic Macedonia,Republic ofMoldova,Turkmenistan, andUzbekistan.

Kazakhstanhas signed but not ratified the protocol. Bosnia and Herzegovina,SerbiaandMontenegro,TajikistanandTurkeyhave no commitments as they did not sign or ratify the Protocol.

Targets

There is no specific numeral target for precipitation.

Related policy documents

• Kyoto Protocol to the UN Framework Convention on Climate Change
  Kyoto Protocol to the United Nations Framework Convention on Climate Change; adopted at COP3 in Kyoto, Japan, on 11 December 1997
• UN Framework Convention on Climate Change
  United Nations Framework Convention on Climate Change
• UNFCCC
  UNFCCC reporting guidelines on annual inventories

Methodology

Methodology for indicator calculation

Data collection and calculation:

Collection of data on the quantity of atmospheric precipitation is carried out by the network of meteorological stations. National hydrometeorological services process the data, assessing their quality and consistency and calculating monthly and annual mean values. Special adjustments are made for 'wetting' and for 'wind losses'. Daily, monthly and annual precipitation quantities are determined. The relationship of the precipitation quantity for a certain period to the perennial standards is calculated as a percentage.

The best practices and concepts for climate monitoring developed in the framework of the Global Climate Observing System (GCOS); the Guide to Meteorological Instruments and Methods of Observation prepared by the Main Geophysical Observatory in coordination with WMO. Climatic standards recommended by WMO are the calculated standards based on 30-year observation data (1961-1990).

Overview of the Projection Models

Projections of the precipitation reported in the National Communications are calculated using a range of Global Climate Models (GCMs).

Mostly for all countries precipitation projections are based on calculations carried out using HadCM3 model (Hadley Centre Coupled Model, version 3), developed by the Hadley Centre in the United Kingdom.

Scenarios and key assumptions

The National Communications present the three most common scenarios: a) baseline scenario or without measures scenario, b) with measures scenario or mitigation scenario, c) with additional measures scenario. These scenarios reflect various hypotheses related to economic growth, population growth, economic and policy development. They also reflect evolution of activities in the energy sector and other non-energy sectors, which contribute to GHG emissions. Each communication describes the national context for all three scenarios in detail.  

The baseline scenario includes all (and only) implemented and current policies and measures as for the time of the development of the national reports, i.g. no assumptions are made on the development and implementation of additional measures and policies in the time horizon considered. Therefore we used these data for our purposes.

Methodology for gap filling

National reports on Climate Change are not available for the following countries: Albania, Bosnia-Herzegovina, Serbia and Montenegro, Tajikistan, Turkey. These countries are not parties of the Kyoto protocol (except Albania) and have no obligations to report to the convention. More detailed information about availability of the national reports can be found here.

The results of the research from individual countries or the projections done by global modeling can be used for gap filling . No gap filling was done at this stage of the project.

It is expected that the Russian Federation will submit its forth national communication in September/ October 2006. Thus there is currently no data on the temperature changes. It is possible to extract the data from the third national communication, but it will not include the current economic development in the Russian Federation and may result in bigger uncertainties in the assessment.

Methodology references

No methodology references available.

Data specifications

EEA data references

• No datasets have been specified here.

External data references

• National Communications on Climate Change

Data sources in latest figures

Uncertainties

Methodology uncertainty

Uncertainties in the projections in precipitation have not been assessed. The methodology and quality of the data differs widely between countries.
Different countries use different methodologies to calculate their projections of the precipitation. It is unclear to which extend the projections form different models are compatible. Simply to compare precipitation for baseline scenario (and across different scenarios) for different countries is not sufficient to shed light on internal consistency, plausibility, and comparability of data and the assumptions behind the scenarios. Analysis of the underlying driving forces (population growth, economic growth, energy consumption, and energy and carbon intensities) should thus also be an important part of the evaluation. Some of these driving forces are specified as model inputs, and some are derived from model outputs, so it is necessary to determine the assumed relationships among the main driving forces.

Data sets uncertainty

1) The dates for submission of the National communications vary from 1998 (Armenia) to 2006 (Belarus, Ukraine, Russia). The models used for calculations of the projected temperature, precipitation and GHG emissions by different countries use different scenarios reflecting various hypotheses related to economic growth, population growth, policy development, evolution of activities in the energy sector and other non-energy sectors, which contribute to precipitation, temperature and GHG emissions. The assumptions for the projection of GHG emission, temperature and precipitation in the National Communications produced in the earlier days may not sufficiently reflect current developments of the countries and additional analysis might be needed. Some for example claim that economic growth in some EECCA and SEE countries was not as high as it was expected and thus the projections of GHG emissions, precipitation  and temperature reported in the communications are higher than the current emission levels.

2) The dates for when simulations were run are unclear. It is however possible to asses the period of the simulation by date of publication of the national communications and the base year used for simulations which are presented in the table below.

Rationale uncertainty

No uncertainty has been specified