Geoscience Reference
In-Depth Information
depletion.would.affect.entire.ecological.communities.(e.g.,.Peters.and.Lovejoy.1992;.
Reaser.and.Blaustein.2005;.Cockell.and.Blaustein.2001).
An.increasing.body.of.evidence.suggests.a.warming.world.accompanying.other.
signiicant. climate. changes. (Intergovernmental. Panel. on. Climate. Change. [IPCC].
2001,.2007)..The.average.global.surface.temperature.rose.by.about.0.74ºC.from.1906.
to.2005.and.was.more.severe.at.higher.northern.latitudes.(IPCC.2007)..Data.for.the.
Northern.Hemisphere.indicate.that.the.last.half.of.the.twentieth.century.experienced.
higher.temperatures.than.at.any.other.time.in.the.past.1300.years.(IPCC.2007)..The.
global.average.sea.level.has.risen.(about.1.8.mm/year.from.1961.to.2003).and.ocean.
heat.content.has.increased.during.the.twentieth.century.(IPCC.2007)..Changes.have.
also.occurred.in.other.aspects.of.climate..For.example,.precipitation.patterns.have.
changed.over.many.regions.of.the.world.(IPCC.2007)..During.the.twentieth.century,.
cloud. cover. has. changed. over. mid. and. high. latitudes.. An. increase. in. the. number.
of.extreme.events.in.weather.and.climate.are.predicted.for.the.twenty-irst.century..
These. include. more. heat. waves,. higher. minimum. temperatures,. fewer. cold. days,.
increases. in. precipitation. at. high. latitudes,. decreases. in. precipitation. on. subtropi-
cal.lands,.and.increased.summer.continental.drying.associated.with.drought.(IPCC.
2007).
Some.of.the.predictions.concerning.global.climate.changes.have.been.supported.
by.recent.studies..For.example,.global.climate.changes.in.temperature.and.precipita-
tion.seem.to.be.inluencing.the.distribution.and.abundance.of.butterlies,.amphibians,.
reptiles,.ish,.and.a.number.of.other.taxa.(e.g.,.Parmesan.1996;.Pounds.et.al..1999;.
Perry.et.al..2005)..Warming.trends.may.have.led.to.the.extinction.of.some.popula-
tions.(Parmesan.1996;.Pounds.et.al..1999;.Thomas.et.al..2006).and.may.be.inluenc-
ing.the.timing.of.breeding.of.others.(Beebee.1995;.Forchhammer.et.al..1998; Crick.
and.Sparks.1999;.Gibbs.and.Breisch.2001;.Blaustein.et.al..2001b;.Post.et.al..2001;.
Chadwick.et.al..2006;.Hušek.and.Adamík.2008).
Increases. in. temperature. and. variability. in. precipitation. (see. Chapter. 1). may.
especially.affect.amphibians.that.are.dependent.on.hydrological.cycles..Changes.in.
precipitation.and.increasing.temperatures.could.alter.connectivity.of.bodies.of.water..
This. could. result. in. either. increasing. or. decreasing. fragmentation. between. bodies.
of. water. and. amphibian. populations.. Long-term. changes. in. temperature. and. pre-
cipitation.could.affect.amphibians.indirectly.in.a.variety.of.ways..Potential.changes.
include.impacts.on.terrestrial.and.aquatic.habitats,.food.webs.and.community-level.
interactions.(e.g.,.competition,.predation),.the.spread.of.diseases,.and.the.interplay.
among.all.these.factors..These.changes.can.inluence.the.interrelationships.of.spe-
cies.occurrences.on.a.landscape.level.and.could.lead.to.range.shifts.of.entire.species.
assemblages.(Raxworthy.et.al..2008;.Seimon.et.al..2007).
Just.as.climate.change.may.have.wide.and.varied.effects.on.numerous.organisms,.
so.might.increasing.UV-B.radiation.(Andrady.et.al..2009)..And.exposure.of.organisms.
to.increasing.UV-B.radiation.is.often.linked.to.luctuations.in.weather.and.changes.in.
climate.(Ovaska.1997;.Kiesecker.et.al..2001;.Andrady.et.al..2009)..In.fact,.the.latest.
United.Nations.panel.on.the.environment.discussed.the.importance.of.the.link.between.
ozone.depletion.and.climate.(Andrady.et.al..2009)..As.the.climate.changes,.so.does.
species'.exposure.to.UV-B.radiation..This.can.occur.independently.of.or.in.concert.
with.changes.in.precipitation.and.temperature.that.can.affect.aquatic.organisms.
