Climate is the long-term weather pattern in a region, typically averaged over 30 years. More rigorously, it is the mean and variability of meteorological variables over a time spanning from months to millions of years. Some of the meteorological variables that are commonly measured are temperature, humidity, atmospheric pressure, wind, and precipitation. In a broader sense, climate is the state of the components of the climate system, including the atmosphere, hydrosphere, cryosphere, lithosphere and biosphere and the interactions between them. The climate of a location is affected by its latitude, longitude, terrain, altitude, land use and nearby water bodies and their currents.
Urban areas usually experience the urban heat island (UHI) effect, that is, they are significantly warmer than surrounding rural areas. The temperature difference is usually larger at night than during the day, and is most apparent when winds are weak, under block conditions, noticeably during the summer and winter. The main cause of the UHI effect is from the modification of land surfaces while waste heat generated by energy usage is a secondary contributor. Urban areas occupy about 0.5% of the Earth's land surface but host more than half of the world's population. As a population center grows, it tends to expand its area and increase its average temperature. The term heat island is also used; the term can be used to refer to any area that is relatively hotter than the surrounding, but generally refers to human-disturbed areas.
A drought is a period of drier-than-normal conditions. A drought can last for days, months or years. Drought often has large impacts on the ecosystems and agriculture of affected regions, and causes harm to the local economy. Annual dry seasons in the tropics significantly increase the chances of a drought developing, with subsequent increased wildfire risks. Heat waves can significantly worsen drought conditions by increasing evapotranspiration. This dries out forests and other vegetation, and increases the amount of fuel for wildfires.
In geomorphology and geology, a peneplain is a low-relief plain formed by protracted erosion. This is the definition in the broadest of terms, albeit with frequency the usage of peneplain is meant to imply the representation of a near-final stage of fluvial erosion during times of extended tectonic stability. Peneplains are sometimes associated with the cycle of erosion theory of William Morris Davis, but Davis and other workers have also used the term in a purely descriptive manner without any theory or particular genesis attached.
The Sahara is a desert spanning across North Africa. With an area of 9,200,000 square kilometres (3,600,000 sq mi), it is the largest hot desert in the world and the third-largest desert overall, smaller only than the deserts of Antarctica and the northern Arctic.
The subtropical zones or subtropics are geographical and climate zones to the north and south of the tropics. Geographically part of the temperate zones of both hemispheres, they cover the middle latitudes from 23°26′09.8″ (or 23.43606°) to approximately 35° north and south. The horse latitudes lie within this range.
A cuesta is a hill or ridge with a gentle slope on one side, and a steep slope on the other. In geology, the term is more specifically applied to a ridge where a harder sedimentary rock overlies a softer layer, the whole being tilted somewhat from the horizontal. This results in a long and gentle backslope called a dip slope that conforms with the dip of resistant strata, called caprock. Where erosion has exposed the frontslope of this, a steep slope or escarpment occurs. The resulting terrain may be called scarpland.
Gloom is a low level of light which is so dim that there are physiological and psychological effects. Human vision at this level becomes monochrome and has lessened clarity.
An aridity index (AI) is a numerical indicator of the degree of dryness of the climate at a given location. The American Meteorological Society defined it in meteorology and climatology, as "the degree to which a climate lacks effective, life-promoting moisture". Aridity is different from drought because aridity is permanent whereas drought is temporary. A number of aridity indices have been proposed ; these indicators serve to identify, locate or delimit regions that suffer from a deficit of available water, a condition that can severely affect the effective use of the land for such activities as agriculture or stock-farming.
The geography of South America contains many diverse regions and climates. Geographically, South America is generally considered a continent forming the southern portion of the landmass of the Americas, south and east of the Colombia–Panama border by most authorities, or south and east of the Panama Canal by some. South and North America are sometimes considered a single continent or supercontinent, while constituent regions are infrequently considered subcontinents.
The Winkler Index, sometimes known as the Winkler Scale or WinklerRegions, is a technique for classifying the climate of wine growing regions based on heat summation or growing degree-days. In the system, geographical areas are divided into five climate regions based on temperature converted to growing degree-days, and is commonly known as Regions I–V. The system was developed at the University of California, Davis by A. J. Winkler and Maynard Amerine.
Rhodes Whitmore Fairbridge was an Australian geologist and expert on climate change. His father was Kingsley Fairbridge.
Climate classifications are systems that categorize the world's climates. A climate classification may correlate closely with a biome classification, as climate is a major influence on life in a region. One of the most used is the Köppen climate classification scheme first developed in 1884.
Texas' weather varies widely, from arid in the west to humid in the east. The huge expanse of Texas encompasses several regions with distinctly different climates: Northern Plains, Trans-Pecos Region, Texas Hill Country, Piney Woods, and South Texas. Generally speaking, the eastern half of the state is humid subtropical, while the western half is largely semi-arid.
Bolam's mouse is a species of nocturnal, burrowing rodent in the family Muridae that inhabits the semi arid and southern arid regions of Australia. It has a number of physiological and behavioural adaptations developed to cope with an extremely varied climate. Including the ability survive by extracting water from seeds alone, the production of highly concentrated urine, low water content faeces and nocturnal activity.
A nephanalysis or neph chart is a type of synoptic chart plotting the types and amount of clouds and precipitation. Nephanalyses may map cloud cover, the altitudes of cloud tops, or cloud ceilings, incorporating data from surface, aerial, and satellite observations. The earliest nephanalyses were based on cloud reports from surface weather stations and were used to study the structure of weather fronts. Satellite observations largely supplanted surface observations for most applications of nephanalysis after 1960, though surface reports remained critical for information relating to cloud bases. The first satellite-based nephanalyses were hand-drawn based on a meteorologist's interpretation of images largely taken in visible light. Nephanalyses based on infrared satellite imagery and automated analyses later emerged as data weather satellites became increasingly abundant.
The climate of Africa is a range of climates such as the equatorial climate, the tropical wet and dry climate, the tropical monsoon climate, the semi-arid climate, the desert climate, the humid subtropical climate, and the subtropical highland climate. Temperate climates are rare across the continent except at very high elevations and along the fringes. In fact, the climate of Africa is more variable by rainfall amount than by temperatures, which are consistently high. African deserts are the sunniest and the driest parts of the continent, owing to the prevailing presence of the subtropical ridge with subsiding, hot, dry air masses. Africa holds many heat-related records: the continent has the hottest extended region year-round, the areas with the hottest summer climate, the highest sunshine duration, and more.
The climate of ancient Rome varied throughout the existence of that civilization. In the first half of the 1st millennium BC, the climate of Italy was more humid and cool than now and the presently arid south saw more precipitation. The northern regions were situated in the temperate climate zone, while the rest of Italy was in the subtropics, having a warm and mild climate. During the annual melt of the mountain snow, even small rivers would overflow, swamping the terrain. The existence of Roman civilization spanned three climatological periods: Early Subatlantic, Mid-Subatlantic (175–750) and Late Subatlantic.
There are numerous effects of climate change on agriculture, many of which are making it harder for agricultural activities to provide global food security. Rising temperatures and changing weather patterns often result in lower crop yields due to water scarcity caused by drought, heat waves and flooding. These effects of climate change can also increase the risk of several regions suffering simultaneous crop failures. Currently this risk is regarded as rare but if these simultaneous crop failures did happen they would have significant consequences for the global food supply. Many pests and plant diseases are also expected to either become more prevalent or to spread to new regions. The world's livestock are also expected to be affected by many of the same issues, from greater heat stress to animal feed shortfalls and the spread of parasites and vector-borne diseases.
Climate change in the Middle East and North Africa (MENA) refers to changes in the climate of the MENA region and the subsequent response, adaption and mitigation strategies of countries in the region. In 2018, the MENA region emitted 3.2 billion tonnes of carbon dioxide and produced 8.7% of global greenhouse gas emissions (GHG) despite making up only 6% of the global population. These emissions are mostly from the energy sector, an integral component of many Middle Eastern and North African economies due to the extensive oil and natural gas reserves that are found within the region. The region of Middle East is one of the most vulnerable to climate change. The impacts include increase in drought conditions, aridity, heatwaves and sea level rise.
