IPCC Report.pdf - Adam Curry

Chapter 3Changes in Climate Extremes and their Impacts on the Natural Physical EnvironmentTable 3-2 | Regional observed changes in temperature and precipitation extremes, including dryness, since 1950 unless indicated otherwise, and using late 20th-century values as reference (see Box 3-1), generally 1961-1990.See Figure 3-1 for definitions of regions. For assessments for small island states refer to Box 3-4.A. North America and Central AmericaRegionsTmax[WD = Warm DaysCD = Cold Days; see Box 3-1] (using late20th-century extreme values as reference,e.g., 90th/10th percentile)Tmin[WN = Warm NightsCN = Cold Nights; see Box 3-1] (usinglate 20th-century extreme values asreference, e.g., 90th/10th percentile)Heat Waves (HW)/Warm Spells (WS)[WSDI = Warm Spell Duration Index,i.e., number or fraction of daysbelonging to spells of at least 6days with Tmax >90th percentile](using late 20th-century extremevalues as reference)Heavy Precipitation (HP)(using late 20th-century extreme valuesas reference, e.g., 90th percentile)Dryness[CDD = Consecutive Dry DaysSMA = (Simulated) Soil MoistureAnomaliesPDSI = Palmer Drought Severity Index;see Box 3-3 for definitions]All NorthAmerica andCentralAmericaW. NorthAmerica(WNA, 3)CentralNorthAmerica(CNA, 4)E. NorthAmerica(ENA, 5)Alaska/N.W. Canada(ALA, 1)E. Canada,Greenland,Iceland(CGI, 2)CentralAmerica andMexico(CAM, 6)High confidence: Likely overall increase in WD,decrease in CD (Aguilar et al., 2005; Alexander etal., 2006).High confidence: Very likely large increases inWD, large decreases in CD (Robeson, 2004;Vincent and Mekis, 2006; Kunkel et al., 2008;Peterson et al., 2008a).Medium confidence: Spatially varying trends.Small increases in WD, decreases in CD in northCNA. Small decreases in WD, increases in CD insouth CNA (Robeson, 2004; Vincent and Mekis,2006; Kunkel et al., 2008; Peterson et al., 2008a).Medium confidence: Spatially varying trends.Overall increases in WD, decreases in CD;opposite or insignificant signal in a few areas(Robeson, 2004; Vincent and Mekis, 2006; Kunkelet al., 2008; Peterson et al., 2008a).High confidence: Very likely large increases inWD, large decreases in CD (Robeson, 2004;Vincent and Mekis, 2006; Kunkel et al., 2008;Peterson et al., 2008a).High confidence: Likely increases in WD in someareas, decrease in others. Decreases in CD insome areas, increase in others (Robeson, 2004;Alexander et al., 2006; Vincent and Mekis, 2006;Trenberth et al., 2007; Kunkel et al., 2008;Peterson et al., 2008a).Medium confidence: Increases in WD, decreasesin CD (Aguilar et al., 2005; Alexander et al.,2006).High confidence: Likely overall decrease inCN, increase in WN (Aguilar et al., 2005;Alexander et al., 2006).High confidence: Very likely large decreasesin CN, large increases in WN (Robeson,2004; Vincent and Mekis, 2006; Kunkel etal., 2008; Peterson et al., 2008a).Medium confidence: Spatially varyingtrends. Small decreases in CN, increases inWN in north CNA. Small increases in CN,decreases in WN in south CNA (Robeson,2004; Vincent and Mekis, 2006; Kunkel etal., 2008; Peterson et al., 2008a).Medium confidence: Weak and spatiallyvarying trends. (Robeson, 2004; Vincentand Mekis, 2006; Kunkel et al., 2008;Peterson et al., 2008a).High confidence: Very likely large decreasesin CN, large increases in WN (Robeson,2004; Vincent and Mekis, 2006; Kunkel etal., 2008; Peterson et al., 2008a).Medium confidence: Small increases inunusually cold nights, decreases in WN innortheastern Canada. Small decreases inCN, increases in WN in southeastern andsouth central Canada. (Robeson, 2004;Vincent and Mekis, 2006; Kunkel et al.,2008; Peterson et al., 2008a).Medium confidence: Decreases in CN,increases in WN (Aguilar et al., 2005;Alexander et al., 2006).Medium confidence: Overall increasesince 1960 (Kunkel et al., 2008). Someareas with significant WSDI increase,others with insignificant WSDI increaseor decrease (Alexander et al., 2006).Medium confidence: Increase in WSDI(Alexander et al., 2006).Medium confidence: Spatially varyingtrends. Some areas with WSDI increase,others with WSDI decrease (Alexander etal., 2006).Medium confidence: Spatially varyingtrends. Many areas with WSDI increase,some areas with WSDI decrease(Alexander et al., 2006).High confidence: Likely increase in manyareas since 1950 (Aguilar et al., 2005;Alexander et al., 2006; Trenberth et al.,2007; Kunkel et al., 2008).Medium confidence: Spatially varyingtrends. General increase, decrease in someareas (Alexander et al., 2006).High confidence: Very likely increase since1950 (Alexander et al., 2006).High confidence: Very likely increase since1950 (Alexander et al., 2006).Low confidence: Insufficient evidence. Medium confidence: Slight tendency forincrease, in southern Alaska; no significanttrend (Kunkel et al., 2008).Medium confidence: Some areas withWSDI increase, most others with WSDIdecrease (Alexander et al., 2006).Low confidence: Spatially varying trends.A few areas increase, a few othersdecrease (Aguilar et al., 2005; Alexanderet al., 2006).Medium confidence: Increase in a few areas(Alexander et al., 2006).Medium confidence: Spatially varyingtrends. Increase in many areas, decrease ina few areas, (Aguilar et al., 2005;Alexander et al., 2006).Medium confidence: Overall slight decreasein dryness (SMA, PDSI, CDD) since 1950;regional variability and 1930s droughtdominate the signal (Aguilar et al., 2005;Alexander et al., 2006; Kunkel et al., 2008;Sheffield and Wood, 2008a; Dai, 2011).Medium confidence: No overall or slightdecrease in dryness (SMA, PDSI, CDD) since1950; large variability, large drought of1930s dominates (Alexander et al., 2006;Kunkel et al., 2008; Sheffield and Wood,2008a; Dai, 2011).Medium confidence: Decrease in dryness(SMA, PDSI, CDD) and increase in meanprecipitation since 1950; large variability,large drought of 1930s dominates(Alexander et al., 2006; Kunkel et al., 2008;Sheffield and Wood, 2008a; Dai, 2011).Medium confidence: Slight decrease indryness (SMA, PDSI, CDD) since 1950, largevariability, large drought of 1930sdominates (Alexander et al., 2006; Kunkelet al., 2008; Sheffield and Wood, 2008a;Dai, 2011).Medium confidence: Inconsistent trends;increase in dryness (SMA, PDSI, CDD) since1950 in part of the region. (Alexander etal., 2006; Kunkel et al., 2008; Sheffield andWood, 2008a; Dai, 2011).Low confidence: Insufficient evidence.Low confidence: Spatially varying trends,inconsistencies in trends in dryness (SMA,PDSI, CDD). (Aguilar et al., 2005; Sheffieldand Wood, 2008a; Dai, 2011).Continued next page191