Congo-Brazzaville - Climate

Lying astride the equator, the country has a tropical climate marked by high temperatures, heavy rainfall, and very high humidity. The seasons are reversed north and south of the equator; the dry season (winter) in the north corresponds to the rainy season (summer) in the south. North of the equator, which runs about 30 miles north of Fort-Rousset, the rainy season lasts from early April until late October and the dry season from early November. to late March. Variations, however, do occur, and certain areas on both sides of the equator have two short wet and two short dry seasons.

Relative humidity is consistently high throughout the country, averaging daily readings of about 80 percent. Temperatures range from 80°F. to 90°F. on the average with only slight variation. In southern portions of the nation the temperatures are somewhat moderated by the Benguela Current, and readings as low as 54°F. have been noted.

Rainfall is in the neighborhood of sixty inches per year, but amounts vary from season to season. In the north precipitation is particularly heavy. During the wet season some portions of the Congo Basin register from five to ten inches per month. Cloudiness, too, is extensive over most of the country, averaging almost 200 days a year. At the beginning and end of the wet seasons, line squalls with winds up to fifty miles per hour can be experienced anywhere, accompanied by violent thunder and lightning.

During the hot, rainy season shrubs, plants, flowers, and young trees grow vigorously, but in the dry season the grasses and under¬growth turn brown, and in exposed areas the land becomes barren. Savanna lands vary in their composition, often containing several types of long grasses as well as many coconut palms and banana trees. Along the fringes of the forests, acacias, lilies, flowering mosses, and many varieties of flowering plants from the periwinkle and ginger families blossom before the advent of the dry season.

In September 2009, Denis Sassou Nguesso, President [for life] of the Republic of Congo, was named the lead spokesperson for the African Union on climate change. The appointment was made at the AU's Special Summit in Tripoli, Libya. Sassou Nguesso launched a new initiative to safeguard the Congo Basin from deforestation, one which unified the six countries that make up the Congo Basin region and presented an African solution to climate change.

The Intergovernmental Panel on Climate Change (IPCC) projected in its fourth Assessment Report (AR4) that mean global temperatures are likely to rise between 1.1 and 6.4°C (with a best estimate of 1.8 to 4°C) above 1990 levels by the end of the 21st century associated with an likely increase in frequency and intensity of extreme climate events (floods, droughts, extreme temperatures etc.).

In the world in general and sub-Saharan Africa in particular, environmental issues interest and influence more and more all the actors of society namely economic policy makers, civil society and government. Congo Brazzaville in general and Brazzaville in particular, which is also one of the cities of developing countries is faced with proven degradation environment problems whose causes are mainly from human activities, natural phenomena and socioeconomic problems. This environmental degradation threatens the health of populations both urban and rural. Drastic measures must be taken against these problems. Thus, an awareness policy and necessary measures must be developed to educate, raise awareness among people to prevent potential hazards related to this issue of environmental degradation that has become worrisome and compromises already the lives of people in the city of Brazzaville particularly.

The country faces an ongoing erosion phenomenon that disrupts the achievement of transport infrastructure. There are generally two types of erosion: Wind erosion and erosion by water or rain erosion.

Wind Erosion is characterized by three phases: firstly, the floor is raised under the aerodynamic action of the wind, the volume of the displaced sand is proportional to the cube of the wind speed. Secondly, the transport phase, the sand forming part of the flow is carried more or less depending on the size and density of the particles. And finally, the third phase, called sedimentation phase, result from both of the loss of power of the wind flow due to weather events related to the topography and evapotranspiration of the plant cover of the area addressed, it also depends on both the size and density of the densest and most coarse particles accumulating faster than finer and lighter particles. Wind erosion is less frequent in Congo.

Rain Erosion is the most common phenomenon in Brazzaville site. It is the object of the evils of Brazzaville’s people. Indeed, atmospheric precipitation is the causative factor of the phenomenon of erosion by water. The nature of the soil, some climate factors, slope, vegetation and man are a set of factors that influence this phenomenon. As for the erosion by water, there are four phases in the gully process by water: the drop effect, sheet erosion, rill erosion and erosion by digging.

This region has been classified to be a region with a less clear picture with respect to projected climate change, with some models projecting an increase in annual total precipitation while others a decrease. So far only a limited number of studies on potential impact of climate change over the Congo region are available.

For most of the assessed parameters the majority of the models has a substantial skill in representing observed conditions. Worst overall performance is definitely visible in the simulation of the intensity of heavy rainfall events that is strongly underestimated in the model ensembles. However this is a known issue and mainly related to the coarse model resolution that dampens the extremes in the model simulations.

Under high emission scenarios, projected changes especially towards the end of the century, are substantially larger over all parts of the domain and remain in the range between about 4°C to more than 5°C (compared to 2°C to 3°C). All temperature changes projected for the scenarios are robust in all seasons. All models agree on a slight decrease in the frequency of cold days and nights and for a substantial increase in the frequency of hot days and nights.

If only the annual average of projected changes is considered, the median projection is for almost no change under the low scenario and for a slight (but mostly robust) tendency for an increase in annual total precipitation (below +10%) in some of the area. However if the changes for the different seasons are included a more diverse picture is given. A strong relative increase in rainfall is projected to occur during the dry season, however it has to be kept in mind that due to the very small rainfall amounts the high relative changes are not at all an indicator of a less-dry future.

In 2008 an enclave of 125,000 gorillas was discovered in the north of the Republic of Congo. In an editorial, the New York Times said the discovery was "extraordinary" and served as "a powerful incentive to create new protected areas to help western lowland gorillas the way other national parks in the Congo Republic have already done." The Goualougo Triangle in the Republic of the Congo is a unique safe haven for endangered gorillas and chimpanzees. It is located a two-day road trip away from the capital of Brazzaville. Some researchers fear climate change might spoil the unspoiled 260-square-kilometer region - the most pristine environment on Earth for endangered great apes.