Strategy Area Description

After geology and habitat pattern, climatic factors are some of the most important influences on the distribution, abundance and behaviour of plant and animal species. 

The strategy area has a temperate climate. Much of the area's weather is tempered by its coastal location, which confers upon it relatively cool summers and mild winters, compared to other areas at a similar latitude. For example, it is cooler than Carlisle in the west but appreciably drier; the strategy area's coastal strip is one of the driest parts of the British Isles. The North Sea's buffering effect extends inland, to some degree, along the river valleys of both the Wear and Tyne.

The North Sea's influence is most evident during the summer, when the coastal strip of South Tyneside and Sunderland experience daytime temperatures some two degrees lower than nearby inland locations. By contrast, in winter, this area experiences fewer extreme low temperatures.

The mean annual temperatures of the strategy area are relatively low, for example mean daily temperatures of 2 to 4˚C in January (the coldest month) and around 15˚C in July/August (the warmest months). The mean highest temperature is around 12.8°C, lower than the England-wide mean of 13.1°C. The mean lowest temperature, of around 7.2°C, is a little higher than that for England generally (5.6°C).

The area's climate is dominated by westerly air flows. For close to two-thirds of a 'normal year' the wind emanates from between south west and north west, bringing much of the area's rainfall. These air flows, after passing over the North Pennines, are warmer and drier before reaching Gateshead, South Tyneside, and Sunderland. Hence, the area experiences less cloud cover, a greater number of sunshine hours and reduced precipitation than locations to the west. The driest months are usually February and April, whilst August is the wettest. The total annual rainfall, of 643.1mm, is considerably lower than England's national mean figure (838.7 mm per annum).

Sunshine levels are lowest in January and December, when day length is shortest. In a clear summer month, the area can experience over 250 hours of sunshine, but the sunniest month, on average, is May.

The extensive urban zones of the strategy area create micro-climatic effects, courtesy of the heat island phenomenon, which effects the ecology of these.

Climate change and biodiversity

The consequences of climate change upon species and habitats in the strategy area, is, at present, indeterminate - but it is clear that there will be impacts and that 'change' is to be expected. Sea level rise will impact all coastal species and habitats, and the tidal reaches of rivers, might suffer 'coastal squeeze'. Storm surges will increase erosive forces which might impact upon mudflats, saltmarshes and other intertidal habitats.

Some of the climate-related pressures which may increase habitat sensitivity include:

• sea-level rise
• 'habitat squeeze'
• temperature stress
• drought
• eutrophication
• increased storms
• invasive species (more of, and better conditions for these)

Recent work indicates that most semi-natural habitats (arable field margins aside) are considered 'medium to highly sensitive' to climate change, and that some future change is 'inevitable'. Furthermore, the condition of each habitats will affect its sensitivity; degraded habitats tending to be less resilient. The most sensitive habitats in the strategy area, in this respect, are probably:

• riverine habitats and standing water bodies (for example lakes and ponds)
• wet woodlands
• wet lowland meadows
• lowland heath, and
• fen, marsh and swamp

Increases in temperature and rainfall patterns could lead to changes in agricultural patterns (for example different crops or harvesting cycles); consequently, some species may no longer be able to inhabit the strategy area. Most exercises in making 'predictions' for the impacts of climate change upon species suggest that changes in range, and behaviour, of some species is likely to occur; in some cases, this may already be underway.  Birdlife International looked at how European bird species might respond to climate change (Huntley and Green et al. 2007). This indicated that the potential future range of the 'average European bird species' might move by nearly 550 km (in a roughly north easterly direction) by the end of the 21^st century.

Whilst the exact response and degree of change taking place cannot yet be accurately predicted, it is anticipated that some of the principal impacts of climate change can be reliably 'anticipated'. Such impacts are likely to include (Hopkins et al., 2007; Smithers et al., 2008):

• changes in the phenology of species and habitats - this may include changes in the timing of seasonal events, for example the flowering of certain plants, which could lead to a loss of synchrony between species and the availability of food and other resources e.g. breeding birds and the availability of the insect larvae (i.e. caterpillars) needed to feed their young
• changes in species' abundance and range, resulting from changes in the availability of the precise climatic conditions required by that, or those, species for example the loss of some breeding seabirds from the strategy area coastline
• changes in the habitat preferences of some species, as microclimates in preferred habitats alter, migrate from one location to another or, in some instances, disappear
• alterations to the habitats themselves, and in some instances whole ecosystems, as biotic systems respond to altered water regimes (for example changes to seasonal rainfall patterns), increased rates of transpiration, decomposition in some habitats and to higher growth rates of some plants
• changes to the composition of some plant and animal communities
• wide scale 'catastrophic' losses in some species, as a consequence of extreme weather events for example droughts, severe snowfall or the incidence of major floods
• the increased survival, spread, or arrival, of invasive species, pest species and disease organisms, for example highly pathogenic avian influenza (HPAI)

As well as negative impacts upon biodiversity, climate change may bring opportunities for some species and habitats. It is anticipated that with change, a suite of new wildlife may 'move north' into the strategy area.  This could mean that the area plays host to a range of attractive new species, which might include colourful invertebrates (for example butterflies and dragonflies) and 'southern' bird species (for example bee-eater), amongst others.